So CopyFail CVE-2026-31431 is a thing.
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@wdormann weird because I had a successful test on up to date f42 yesterday …
@letoams
Got a snapshot that you can revert to?
I'd like to see the evidence (along with showing the current kernel version). -
@gregkh @joshbressers @wdormann @Viss so there's absolutely no middle ground? When there is clearly a bug with security impact, give the distros list a week notice (two weeks max, per their policy). If it leaks, outcome is no worse than not notifying distros. The researcher can even do it instead of the kernel. At scale (Linux!) this seems like a Pareto distribution: major distros cover disproportionally most users.
@zmanion @joshbressers @wdormann @Viss Why is linux-distros somehow "special" enough to get these types of announcements and not everyone else? How exactly would you explain that to your favorite government entity? -
@letoams
Got a snapshot that you can revert to?
I'd like to see the evidence (along with showing the current kernel version).@wdormann it seemed my VM was on 6.18.7–100 and hadn’t pulled in the updates yet
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There's also a C version of it that works quite well. Even supports aarch64.
The CEO of Theori / Xint has a damage-control thread explaining why they chose to release the vulnerability details in a way that left all of the Linux distros in the dark.
TL;DR: With AI in the mix, the old way of coordinating vulnerabilities doesn't scale anymore.
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@k8ie
Yes, it's clear that it was published as a "Look at us!" vehicle.But their abysmally bad coordination put every Linux user on the planet at risk, and is clear evidence that they don't care about anybody other than themselves.
@wdormann @k8ie From what I've seen having been volunteered to be our infosec d00d, quarterbacking a coordination of affected downstream parties can sometimes be a big PITA. But no familiarity with the linux kernel CVD process - I presume its not as onerous as these guys are claiming?
Like.. isn't there a dist.list/channel that all distro maintainers hang out on? call a meeting, answer questions, set a timetable, take minutes... pain yes but not that hard..?
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The CEO of Theori / Xint has a damage-control thread explaining why they chose to release the vulnerability details in a way that left all of the Linux distros in the dark.
TL;DR: With AI in the mix, the old way of coordinating vulnerabilities doesn't scale anymore.
@wdormann TL;DR: lame AI excuse award for laziness and incompetence
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@wdormann TL;DR: lame AI excuse award for laziness and incompetence
@ReneRebe
Yeah.I mean, fine, you can say that Qualys is doing it this way too. But TBH, I got the impression that the Qualys example was found after the fact when everything blew up, as opposed to purposefully modeling your workflow after Qualys.
But the real red flag is this:
Patch first. Update your distribution's kernel package to one that includes mainline commit a664bf3d603d — it reverts the 2017 algif_aead in-place optimization, so page-cache pages can no longer end up in the writable destination scatterlist. Most major distributions are shipping the fix now.No human being on the planet would have concluded such a thing. Anyone with half a wit would know for a fact that no distribution had updates at the time that copy.fail was published. Not even one of the FOUR DEMO DISTROS IN THE PAGE ITSELF.
️This all was AI-driven YOLO attention seeking, and the linked thread from Brian is just damage control.
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The CEO of Theori / Xint has a damage-control thread explaining why they chose to release the vulnerability details in a way that left all of the Linux distros in the dark.
TL;DR: With AI in the mix, the old way of coordinating vulnerabilities doesn't scale anymore.
@wdormann Hi Will. Shouldn't/couldn't the Linux security team have imposed an embargo and coordinated with the distro's?
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@wdormann Hi Will. Shouldn't/couldn't the Linux security team have imposed an embargo and coordinated with the distro's?
@aristot73
In an ideal world, yes.
But they're not interested in doing such things.
For reasons, presumably.
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@aristot73
In an ideal world, yes.
But they're not interested in doing such things.
For reasons, presumably.@wdormann wow....
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While this vulnerability seems to be discovered using AI ("Xint Code"), I have to assume that they also let the AI decide how to do the vulnerability coordination as well.
major builds are out as of this writing
No distros have official updates for CVE-2026-31431. Fedora 42 and newer have updates, but no official advisory or acknowledgement of CVE-2026-31431. So with them it's unclear if it's even intentional. Red Hat, Ubuntu, Amazon Linux, and Suse all have advisories as of now, but NO updates.disable the algif_aead moduleas a mitigation.
Bespoke distros like RHEL don't use a module, it's compiled into the kernel.
I can't figure out what the Xint Code angle is with this copyfail stuff. On one hand, yes, it is a true vulnerability that affects a LOT of Linux distros available. And they did submit the bug for fixing to the upstream kernel people.
BUT the CVE has only existed for a week. And NONE of the distros IN THEIR ADVISORY had updates available at the time that they pulled the trigger for publication of the shiny copy.fail website.
I struggle to think of how this even happens. In all my years of infosec, you're either on board with doing CVD (e.g. coordinating with the former CERT/CC) or you're not (dropping 0day). But this all fits bizarrely in the middle. The publication gives the guise that they did the right thing, (and please use our AI services). But at the same time, they clearly chose to release the vulnerability details and functional exploit before any distro had the ability to properly do anything about it.
Either these Xint Code (Theori) people have a hidden agenda or ulterior motive that we aren't aware of yet. Or they're just really bad at coordinated vulnerability disclosure. You pick.
@wdormann What really shit me off about the thing is the PoC test code they published.
They suggest you run it by curl'ing a URL from their site, directly into python and su.
On a vulnerability that's a fastpath to root.
But it gets better because you look at the code and it's obfuscated? No comments, no detail, compacted as much as possible for python.Okay, it's fairly basic obfuscation, I could work it out in a few minutes.
It runs an x86_64 ELF binary, that it ships as hex-encoded zlib.
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@wdormann What really shit me off about the thing is the PoC test code they published.
They suggest you run it by curl'ing a URL from their site, directly into python and su.
On a vulnerability that's a fastpath to root.
But it gets better because you look at the code and it's obfuscated? No comments, no detail, compacted as much as possible for python.Okay, it's fairly basic obfuscation, I could work it out in a few minutes.
It runs an x86_64 ELF binary, that it ships as hex-encoded zlib.
@wdormann Just incase I need to say this for anyone, and I'm really hoping I don't.
I've never seen a worse PoC code. You are supposed to ship extremely readable, well documented code that demonstrates procedure of the exploit.
You do not suggest people fucking blindly run it from a URL directly onto a machine, without any visibility into what's even running???
I've never heard of a quicker way of getting your machines shoved into a botnet.
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The CEO of Theori / Xint has a damage-control thread explaining why they chose to release the vulnerability details in a way that left all of the Linux distros in the dark.
TL;DR: With AI in the mix, the old way of coordinating vulnerabilities doesn't scale anymore.
"From that prior experience, we assumed distros had ways to learn about upstream security-critical bugs. We never needed to notify them explicitly before."
Which roughly translates as : "We know nothing of how the linux dev ecosystem works and do not care."
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Unlike what the buffoons at Theori published as a "mitigation", the folks at Red Hat actually published a viable mitigation for CopyFail CVE-2026-31431.
Specifically, edit your grub (or whatever you use to load your kernel) configuration to have one of the following arguments:
initcall_blacklist=algif_aead_initinitcall_blacklist=af_alg_initinitcall_blacklist=crypto_authenc_esn_module_initWith such boot arguments to the Linux kernel, the affected bits won't be reachable.
@wdormann They are suboptimal at web design, though.
(First time I see this, I didn’t even know it was possible. It doesn’t change anything to the good they’re doing, obviously, it’s just funny.)
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The CEO of Theori / Xint has a damage-control thread explaining why they chose to release the vulnerability details in a way that left all of the Linux distros in the dark.
TL;DR: With AI in the mix, the old way of coordinating vulnerabilities doesn't scale anymore.
@wdormann the thing I don't get about this whole situation is, if they really are genuine in their plight to make the world a better place (which doesn't not preclude making "paid for" products), I don't see why they can't raise awareness of what they perceive is a critical issue without just dropping the PoC. They're mutually exclusive and plenty of people have successfully done exactly that, while holding back the exact details until later. Sure, other people will poke if given vague direction but the damage and panic is done by making it instantly and easily achievable.
Even with the context continually being given and expanded on, it still feels like nothing more than an excuse for attention to "buy our awesome product" through thinly veiled bragging rights.
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The CEO of Theori / Xint has a damage-control thread explaining why they chose to release the vulnerability details in a way that left all of the Linux distros in the dark.
TL;DR: With AI in the mix, the old way of coordinating vulnerabilities doesn't scale anymore.
@wdormann if these ai systems are so fast, cheap, and omnipotent, it seems like they couldve used "xint" to determine that downstream hadn't patched yet
ai changes the equation, okay fair enough. we were also completely naive, our powerful ai kept us out of the loop🤨 -
@wdormann @joshbressers @Viss I love it how people think that "coordination of vulnerabilities" is actually something that can be done these days. Think of just who uses the software in question, and who should, and should not, be on such a list to get a "early disclosure notification".
As I have said for quite some time now, all early-disclosure lists are leaks, otherwise why would your government allow them to be in existence?
Software, and specifically open source software, runs the world. So should the whole world be on that notification list?
This post got into my head. I think you're right, the days of coordination are over
So I wrote it down
https://opensourcesecurity.io/2026/05-vulnerability-economics/ -
This post got into my head. I think you're right, the days of coordination are over
So I wrote it down
https://opensourcesecurity.io/2026/05-vulnerability-economics/@joshbressers @gregkh @wdormann @Viss Nice, just my conclusion: if embargoes ever made sense, that time is over.
#curl notifies distros about upcoming CVEs, but a good part of curl applications will notice them a year (or ten) from now. Maybe. They probably just update to a newer version without reading the CVEs.
️(I hold special views about LTS releases with hand-picked patches - but maybe another time
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This post got into my head. I think you're right, the days of coordination are over
So I wrote it down
https://opensourcesecurity.io/2026/05-vulnerability-economics/@joshbressers @gregkh @wdormann @Viss aren’t the "users" missing from the equation? In the end we do it for them and we need them to fix their systems, and we need it to be easy for them to fix their systems.
Also there are a lot of open source companies, whether software developers, support providers, integrators, administrators, or a combination.
Also governments which are users, regulators, contributors…
Economics are hard indeed
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@joshbressers @gregkh @wdormann @Viss Nice, just my conclusion: if embargoes ever made sense, that time is over.
#curl notifies distros about upcoming CVEs, but a good part of curl applications will notice them a year (or ten) from now. Maybe. They probably just update to a newer version without reading the CVEs.
️(I hold special views about LTS releases with hand-picked patches - but maybe another time
)@icing @joshbressers @gregkh @wdormann @Viss All these arguments may or not be true, but I still do not quite see why - for copy fail - downstream open-source projects such as Debian were not notified during the embargo time?
