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VulnerabilityPublished Updated

CVE-2026-74338: Linux kernel · bpf: Reject sleepable BPF_LSM_CGROUP programs at load time

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in f0a49d16804d319774388a32d8cdcef319a9e481 : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in f0a49d16804d319774388a32d8cdcef319a9e481, be9eaf2bb5db4ad3de61ef739fd268fd7f135737, b4059a1f57eff3e206d44697f64ad81076512760 +2
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e, < f0a49d16804d319774388a32d8cdcef319a9e481
Fixed in
  • f0a49d16804d319774388a32d8cdcef319a9e481
LinuxLinuxAffected
  • ≥ 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e, < be9eaf2bb5db4ad3de61ef739fd268fd7f135737
Fixed in
  • be9eaf2bb5db4ad3de61ef739fd268fd7f135737
LinuxLinuxAffected
  • ≥ 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e, < b4059a1f57eff3e206d44697f64ad81076512760
Fixed in
  • b4059a1f57eff3e206d44697f64ad81076512760
LinuxLinuxAffected
  • ≥ 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e, < 5b038319be442c620f774e6fc9e9283deeca1c75
Fixed in
  • 5b038319be442c620f774e6fc9e9283deeca1c75
LinuxLinuxAffected
  • ≥ 69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e, < 4b9d8bdeb19e709f9bc3c317d48b0c0add3b2b1d
Fixed in
  • 4b9d8bdeb19e709f9bc3c317d48b0c0add3b2b1d
LinuxLinuxAffected
  • =6.0
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject sleepable BPF_LSM_CGROUP programs at load time The cgroup shim runs under rcu_read_lock_dont_migrate(), so we should not attach any sleepable BPF programs there. Add support to the verifier to explicitly reject attempts to load sleepable BPF programs destined for LSM cgroup attachment. Without this, we get the following splat from a BPF_LSM_CGROUP program marked BPF_F_SLEEPABLE attached to file_open when it calls bpf_get_dentry_xattr(): BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1567 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 34317, name: load preempt_count: 0, expected: 0 RCU nest depth: 2, expected: 0 Call Trace: down_read+0x76/0x480 ext4_xattr_get+0x11f/0x700 __vfs_getxattr+0xf0/0x150 bpf_get_dentry_xattr+0xbb/0xf0 bpf_prog_e76a298dac9218c6_test_open+0x6a/0x85 __cgroup_bpf_run_lsm_current+0x326/0x840 bpf_trampoline_6442534646+0x62/0x14d security_file_open+0x34/0x60 do_dentry_open+0x340/0x1260 vfs_open+0x7a/0x440 path_openat+0x1bac/0x30a0 libbpf provides a .s named section variant for every sleepable program type except lsm_cgroup, reflecting that per-cgroup LSM programs are intended to only run in a non-sleepable context. The above splat was obtained by bypassing libbpf by using bpf(2) directly.

References

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