CVE-2026-80928: Linux kernel · smack: fix cred UAF in smack_file_send_sigiotask()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 11 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix for this vulnerability has been implemented in the Linux kernel by modifying smack_file_send_sigiotask() to always access the objective credentials. Users should apply the official kernel update containing this fix once available. Patch status is not explicitly confirmed in the provided data; check the vendor advisory or Linux kernel mailing lists for the official patch and update guidance.
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.
References
- nvd.nist.gov/vuln/detail/CVE-2026-80928 (opens in a new tab)
- git.kernel.org/stable/c/b5bcf3adfa27279da4401ab8f1e1a706601a92be (opens in a new tab)
- git.kernel.org/stable/c/b791401bf389a1546a830d2b381ca60fe94c7870 (opens in a new tab)
- git.kernel.org/stable/c/ed64aa505875a3b4defd504ee8e59e1949246a62 (opens in a new tab)
- git.kernel.org/stable/c/fedc88e38ce979a720cd2de042578cb5df3dc8de (opens in a new tab)
- ubuntu.com/security/CVE-2026-80928 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-80928 (opens in a new tab)
- git.kernel.org/linus/fedc88e38ce979a720cd2de042578cb5df3dc8de (opens in a new tab)