CVE-2026-80928 (CVSS 7.8)

Description

In the Linux kernel, the following vulnerability has been resolved: smack: fix cred UAF in smack_file_send_sigiotask() When inspecting the credentials of another task, objective credentials (->real_cred, accessed with __task_cred()) must always be used. Accessing ->cred on a non-current task is forbidden unless that task is being created or destroyed; a task is allowed to change its own ->cred pointer with no synchronization, and changing ->cred should only affect the current syscall. smack_file_send_sigiotask() was accessing both sets of credentials: First tsk->cred, then __task_cred(tsk). Fix it, always access the objective credentials here. I have tested that this bug can lead to a KASAN-reported UAF of struct cred in smack_file_send_sigiotask(), and that this fix prevents the race.

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CVSS v3.1 Score

7.8

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0013

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/7c7fe043f3099d0d35002b248967f75e55345b93 https://git.kernel.org/stable/c/a512366d84e134a9eefc2cc40eeb6e80e2ec162c https://git.kernel.org/stable/c/b5bcf3adfa27279da4401ab8f1e1a706601a92be https://git.kernel.org/stable/c/b791401bf389a1546a830d2b381ca60fe94c7870 https://git.kernel.org/stable/c/ed64aa505875a3b4defd504ee8e59e1949246a62 https://git.kernel.org/stable/c/f9c7b1f2b9d8f4176d2632743f51400855978ace https://git.kernel.org/stable/c/fedc88e38ce979a720cd2de042578cb5df3dc8de

Frequently Asked Questions

What is CVE-2026-80928? +

In the Linux kernel, the following vulnerability has been resolved: smack: fix cred UAF in smack_file_send_sigiotask() When inspecting the credentials of another task, objective credentials (->real_cred, accessed with __task_cred()) must always be used. Accessing ->cred on a non-current task is forbidden unless that task is being created or destroyed; a task is allowed to change its own ->cred pointer with no synchronization, and changing ->cred should only affect the current syscall. smack_file_send_sigiotask() was accessing both sets of credentials: First tsk->cred, then __task_cred(tsk). Fix it, always access the objective credentials here. I have tested that this bug can lead to a KASAN-reported UAF of struct cred in smack_file_send_sigiotask(), and that this fix prevents the race. It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-80928? +

CVE-2026-80928 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0013, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-80928? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-80928