Abdul Karim

Linux Engineer. In spare time trying to run this charity, @official_auf
Occasionally tweet about tech.
#LFC fan.

[International Cyber Digest @IntCyberDigest]

‼️🚨 BREAKING: An AI found a Linux kernel zero-day that roots every distribution since 2017. The exploit fits in 732 bytes of Python. Patch your kernel ASAP.

The vulnerability is CVE-2026-31431, nicknamed "Copy Fail," disclosed today by Theori. It has been sitting quietly in the Linux kernel for nine years.

Most Linux privilege-escalation bugs are picky. They need a precise timing window (a "race"), or specific kernel addresses leaked from somewhere, or careful tuning per distribution. Copy Fail needs none of that. It is a straight-line logic mistake that works on the first try, every time, on every mainstream Linux box.

The attacker just needs a normal user account on the machine. From there, the script asks the kernel to do some encryption work, abuses how that work is wired up, and ends up writing 4 bytes into a memory area called the "page cache" (Linux's high-speed copy of files in RAM). Those 4 bytes can be aimed at any program the system trusts, like /usr/bin/su, the shortcut to becoming root.

Result: the next time anyone runs that program, it lets the attacker in as root.

What should worry most: the corruption never touches the file on disk. It only exists in Linux's in-memory copy of that file. If you imaged the hard drive afterwards, the on-disk file would match the official package hash exactly. Reboot the machine, or just put it under memory pressure (any normal system load that needs the RAM), and the cached copy reloads fresh from disk.

Containers do not help either. The page cache is shared across the whole host, so a process inside a container can use this bug to compromise the underlying server and reach into other tenants.

The original sin was a 2017 "in-place optimization" in a kernel crypto module called algif_aead. It was meant to make encryption slightly faster. The change broke a critical safety assumption, and nobody noticed for nine years. That bug then rode every kernel update from 2017 to today.

This vulnerability affects the following:
🔴 Shared servers (dev boxes, jump hosts, build servers): any user becomes root
🔴 Kubernetes and container clusters: one compromised pod escapes to the host
🔴 CI runners (GitHub Actions, GitLab, Jenkins): a malicious pull request becomes root on the runner
🔴 Cloud platforms running user code (notebooks, agent sandboxes, serverless functions): a tenant becomes host root

Timeline:
🔴 March 23, 2026: reported to the Linux kernel security team
🔴 April 1: patch committed to mainline (commit a664bf3d603d)
🔴 April 22: CVE assigned
🔴 April 29: public disclosure

Mitigation: update your kernel to a build that includes mainline commit a664bf3d603d. If you cannot patch immediately, turn off the vulnerable module:

echo "install algif_aead /bin/false" > /etc/modprobe.d/disable-algif.conf
rmmod algif_aead 2>/dev/null || true

For environments that run untrusted code (containers, sandboxes, CI runners), block access to the kernel's AF_ALG crypto interface entirely, even after patching. Almost nothing legitimate needs it, and blocking it shuts the door on this whole class of bug...

[NADA 𓂆 @nadaa01012]

This little girl says, “I’m scared,” I want my mom back،،،💔
If you’re scrolling, PLEASE leave a dot..

[usaama @yoUsaama]

sometimes when i wanna be left alone i break into three of my neighbors' homes and stay there indefinitely

[Abdul Karim @1akarim]

@TotalGiving your site certs have expired, anyone can take a look?
https://t.co/fDVYrskbAh?

[Bushra Shaikh @Bushra1Shaikh]

@EylonALevy 36 young girls have just been killed in Minab city- that's murder not liberation you utter scumbag.

[Tehran Tadhg @TadhgHickey]

Just wondering if the 52 schoolgirls you just slaughtered in Minab were on the list of Iranians you were trying to rescue?

[Mehdi Hasan @mehdirhasan]

They illegally bomb another country without any justification, for the second year running, and then they put out videos as if they’re the innocent victims. Beyond parody.

[Pistachio 🇮🇷 🇵🇸 @HarleyShah]

Iran has not attacked a country unprovoked in it's 5000 year old history. Israel has attacked six in one year. Who is the threat here?

[Abdul Karim @1akarim]

https://t.co/92U7sDhfqt

[Pistachio 🇮🇷 🇵🇸 @HarleyShah]

Iran has not attacked a country unprovoked in it's 5000 year old history. Israel has attacked six in one year. Who is the threat here?

[Mohamad Safa @mhdksafa]

Imagine if Iran bombed Washington and killed students in schools, what would you call it? Terrorists

The U.S. and Israel bombed Tehran and killed students in schools. Why do you call it a "pre-emptive strike"?

Bombing a school is a war crime under international humanitarian law

[SV *Champions of England* @SVCarbaholic]

There’s always a tweet

[Globe Eye News @GlobeEyeNews]

BREAKING:

51 Iranian children killed, 60 students wounded after joint US-Israel strikes hit girls' school in Iran.

[Fiona Lali @fiona_lali]

Do not bother watching this vile statement.

He condemns Iran. Not the US/Israeli strikes that have MURDERED school girls in Minab.

This is the servile position of British capitalism, following its US master. He confirms British planes are in the sky.

HANDS OFF IRAN!

[Donald J. Trump @realDonaldTrump]

Remember that I predicted a long time ago that President Obama will attack Iran because of his inability to negotiate properly-not skilled!

[JonnyUtd @Fx1Jonny]

Truly heartbreaking scenes as Iranian fathers go through the school bags of the 86 children Trump brutally murdered.

Unforgivable them kids did nothing to him!

[Masjid al Aqsa @firstqiblah]

Israeli entity imposes a lockdown on Masjid al-Aqsa using its aggression on Iran as a pretext.

[John Cusack @johncusack]

No more schools to blow up in Gaza

[Jeremy Corbyn @jeremycorbyn]

The illegal attack on Iran by Israel and the United States is a catastrophic act of aggression, brutality and escalation. Human beings will pay the price.

[Elaine Molyneux @molyneux_elaine]

Please sign and share