21 comments

  • ataraxia937 1 hour ago
    This one again feels overblown, at least for servers. I just checked an org of over 200 GitHub repos. Node, Python, and C#. None of them are vulnerable... because none of them actually call the Brotli decoder. It's just not enabled by default on the server side, by the platforms themselves. This is much like the PHP bugs, where specific conditions have to be in play before you're actually vulnerable.

    For clients? Sure, that's a bigger risk. Patch them. But bad guys aren't attacking your clients unless the clients connect to them. Don't stay up late to fix this.

    (And yes, .NET is included here, because Microsoft's Brotli module is a binding for Google's vulnerable reference implementation.)

    • guac 25 minutes ago
      Doesn't node's fetch call the decoder automatically for `br` responses? So any attacker controlled content that a server fetch's may be vulnerable?
    • babuskov 1 hour ago
      How did you check? Is there are PoC or some kind of command to run?
    • bbor 1 hour ago
      I mean, I dare say the 4,200,000 Python servers built yesterday alone with this package might disagree...? https://pypistats.org/packages/brotli

      I can't find download numbers for extras, but it comes in the pretty dang innocuous-seeming `aiohttp[speedups]`, as well. Also `urllib3[brotli]`. Many, many people will be running these servers without recognizing the name of the library, especially in the agentic era.

      I might be missing something obvious in your message, cause I don't see why server/client is relevant. Why would a frontend app speak a protocol that the backend doesn't?

      • deathanatos 1 hour ago
        That's just the total number of times that package was downloaded, which is completely unrelated to how many servers it appears in? Same with `aiohttp`: aiohttp can be used as a client library.

        Sure, people should check their dependency trees, and make informed decisions.

      • vinyl7 44 minutes ago
        The whole package manager system is a complete disaster. A huge number of dependencies are pulled in that go unused in most projects, so the number of downloads is an extremely unreliable number. I'd be surprised if more than 10% of those downloads actually use the brotli decoder.
  • anonymous908213 2 hours ago
    I could do without every memory bug getting a cute sensational name and marketing push, I have to say.
    • aaronbrethorst 1 hour ago
      We should start naming them like hurricanes: NIST creates a list of alphabetical names and assigns any CVE >= 9.0 with a name. Vulnerability Alex (CVE 9.4)
      • ks2048 53 minutes ago
        Vulnerability Zzyzx in a week
        • nevir 23 minutes ago
          Tomorrow
    • lovich 2 hours ago
      that ship sailed a while ago. Rowhammer is the first one I can remember
      • vinkelhake 2 hours ago
        Let's not forget about heartbleed!
        • judge2020 2 hours ago
          Back in the email days the virus authors named them, e.g. YouAreAnIdiot, ILoveYou
          • Waterluvian 1 hour ago
            The Blaster virus was a fun one.
        • mhio 2 hours ago
          That was the first exploit logo I can recall
          • weinzierl 1 hour ago
            The most memorable one for me is DirtyCOW.
      • card_zero 18 minutes ago
        Rowhammer was kind of special, surely, what with being based on a physical design flaw?
  • rvanlaar 3 hours ago
    It looks like brotli <= 1.2.0 is vulnerable.

    The python package has already been updated to 1.2.1. https://pypi.org/project/brotli/1.2.1/

  • hatthew 1 hour ago
    I feel like normal security issues don't get much publicity. The PHP and eMudhra issues seemed severe, and worth publicity. But then with things like this, I'm not sure. Is this a severe issue? Or is it just a run of the mill issue that's only newsworthy because web security is on people's minds right now?
    • Gigachad 1 hour ago
      The whole industry is on edge right now, and numbers wise the CVE count has exploded beyond belief. It's probably to take the side of caution, treat everything as important and update everything promptly rather than the old way of doing things where libraries are left months or years out of date until something happens.
  • kccqzy 2 hours ago
    There’s apparently no writeup on exactly what was the fix. So I’m going to make a guess that this is the chromium commit that fixed the problem: https://source.chromium.org/chromium/chromium/src/+/224140d4...

    And this commit contained a refactoring from BROTLI_BOOL to BrotliDecoderErrorCode so the situation was that probably one of the error conditions previously simply returned false but needed more detail about what went wrong to continue safely.

    Well okay this change from `if (prev_ix < cur_ix)` to `if (prev_ix < cur_ix && cached_backward <= max_backward)` is also suspicious and could be an related or unrelated hardening fix.

  • adzm 3 hours ago
    Interestingly the commit that fixes this in brotli dates back to February https://github.com/google/brotli/commit/0ed4268a4401abcb4472...
    • cowlevel 2 hours ago
      OpenAI's tweet says it wasn't recognized as security relevant so wasn't important enough to make a release - until their agent realised it was.

      https://nitter.jaydenha.uk/OpenAI/status/2113766354386084338

      • dofm 2 hours ago
        Until their agent realised there was a good chance of a press release in it.
        • robswc 39 minutes ago
          I am just amazed at how many people are blind to this.

          Every single time one of these labs does something it is almost always sensationalized. They absolutely cannot refrain from describing how incredible their models are, it has to be injected into everything. I get this is basic grow-your-company stuff but it is getting obnoxious.

        • SV_BubbleTime 1 hour ago
          Chat, we need to constantly be justifying our absolutely absurd IPO. Use UltraMegThink and reference the ExploitToGetUsRegualtoryCapture.md. kkthnx
  • Sytten 3 hours ago
    Since I checked Rust servers should be fine since the brotli crate is not a binding on the C.
    • doodlesdev 1 hour ago
      Apparently it doesn't contain a binding to the C library, but it does contain some compatibility and shares design decisions with it. In other words, it's not a clean-room implementation from the spec, but rather it's a port. Since this RCE is triggered by a OOB access, it's unlikely to have made it into the crate, but it's good to keep these things in mind.
    • octoberfranklin 12 minutes ago
      Nope, run ldd on cargo; it links to libbrotlidec.so.1. Via libcurl.

      Aren't you glad cargo connects to the network whenever it feels like it? I just love it when my build tool does that.

      There are 753 crates that drag in brotli this way: https://lib.rs/crates/curl/rev

      The real killer is the oath crate. Basically every rust project using OAuth is vulnerable. That's 398 projects on crates.io plus who knows how many binaries (a lot of non-library projects don't bother publishing to crates.io).

      Another scary one is "a practical HTTP client that is fun" https://lib.rs/crates/isahc used in 317 crates including sequoia. In case you wanted somebody to steal your private keys.

  • kylepomykala 2 hours ago
    They just keep coming, don't they?
    • Gigachad 1 hour ago
      For as long as we still have C code accessible to the internet.
    • hoppp 2 hours ago
      Never gonna stop. Consider it normal. Hey, at least humans still have a job. Incident response
      • awakeasleep 2 hours ago
        Let's not kid ourselves, llm's are already doing the incident response for this in many infrastructure teams
        • chelmzy 1 hour ago
          I would love to hear your definition of this. Are llms used to aid in incident response? 100%. Why would I sit there and manually review data from multiple sources when I could have an agent pull from all and summarize? But to hand it off end to end? I haven't seen anyone accomplish this.
        • hoppp 2 hours ago
          But they don't respond with fear and flailing arms!
  • 0xbadcafebee 14 minutes ago
    If you are using Python, you are affected if you use urllib3, requests, httpx, aiohttp, Scapy, and others, if they were installed when Brotli was also installed. You can mitigate by uninstalling brotli and brotlicffi, OR, strip `br` from Accept-Encoding on outbound AND reject `Content-Encoding: br` on inbound.

    This is not a server-side issue (unless for some weird reason you're using Brotli decoding in your http request processing), it's client-side.

    Thank you Paul for the write-up (https://opensourcemalware.com/blog/node2shell-affects-python)

  • cowlevel 4 hours ago
    Likely mitigation: disable brotli (br) content-encoding on both sides
    • thayne 2 hours ago
      Unfortunately, AFAICT, there is no way to do this for node's fetch. I suspect there are other client libraries that don't have a way to disable it.
  • csiegert 1 hour ago
    Is Deno affected, too? It uses brotli by default. But I don’t know how it is implemented.
    • gnabgib 1 hour ago
      Deno is dead (baby)

      > We will support the Deno runtime for another year with monthly releases containing bug fixes and security updates. After that year we will end our development

      https://deno.com/blog/cloudflare

      • csiegert 58 minutes ago
        I know that it is dead but since they provide security updates for another year I haven’t migrated off of it immediately. Anyways, the Deno runtime uses a brotli Rust crate that does not wrap C code, and with unsafe off, so I assume it is safe.
        • gnabgib 55 minutes ago
          So a person of rhetorical questions? Great
          • csiegert 41 minutes ago
            No. After your unhelpful answer I started investigating if my deployment is affected.
    • Amsozzer 1 hour ago
      I doubt it
  • VladVladikoff 37 minutes ago
    >A significant blast radius

    Is it really so hard to write a 2 sentence tweet that you need an AI to do it for you?

  • dboreham 2 hours ago
    This is a better article: https://www.aikido.dev/blog/python-packages-vulnerable-node2...

    and this is the actual CVE report, which doesn't say much: https://www.cve.org/CVERecord?id=CVE-2026-111497

  • cpburns2009 2 hours ago
  • QuadmasterXLII 3 hours ago
    is flask hello world with gunicorn behind apache vulnerable?
    • cpburns2009 2 hours ago
      Only decompression with Google's brotli library is affected. So if you use "Brotli" or "brotlicffi" in your Python app to decompress brotli, you're vulnerable. Compressing responses with brotli from Apache is safe.
    • TZubiri 3 hours ago
      what I can say is that a 5 liner hello world starting with ‘import socket’ is not affected

      whether a hello wolrd in fastapi is affected might also be interesting

  • bogomind 3 hours ago
    [flagged]
  • bibekadhikari 3 hours ago
    [flagged]
    • thayne 2 hours ago
      > refusing br content-encoding at the edge seems like the fastest mitigation.

      That's pretty difficult if you make outbound requests, and don't already have a TLS interception proxy set up.

    • cowlevel 2 hours ago
      This is an AI karmabot comment, it should remain flagged
  • DogeGode 3 hours ago
    Another day, another buffer-overflow vulnerability in C code …
  • profdevloper 3 hours ago
  • userbinator 1 hour ago
    Brotli, another one of those pseudostandards[1] from Big G that I was avoiding all along. Dodged another bullet.

    [1] When more than half of the "standard" https://www.rfc-editor.org/info/rfc7932/#page-44 is an opaque binary blob, they're really not encouraging independent implementations.

    Edit: the votes really show what an echochamber for Big G this place has become. FUCK YOU, GOOGLE!

    • johncolanduoni 33 minutes ago
      How do you suggest they provide the static compression dictionary?
      • userbinator 2 minutes ago
        You don't. Any real compression algorithm, including all the other standard ones, doesn't need such a thing.