CVE-2026-89738: Linux kernel · usb: gadget: at91_udc: drain polled-VBUS timer/work before udc is freed
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in c27d13ce4bab80fbdf6523928071b6c24b37606c : patch Linux kernel soon.
Data as of 26 Oct 2026, 19:51 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in c27d13ce4bab80fbdf6523928071b6c24b37606c, a2a602cb1e28d76a5398cec3fa21b0110385f501, 723d73b245843d4fff4c3f42e857c78c2b2d414e +2
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
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in– |
AI-suggested
A fix is available and has been applied in Linux kernel versions after 2.6.36. Users and administrators should update to a fixed kernel version containing the patches identified by the commits c27d13ce4bab80fbdf6523928071b6c24b37606c, a2a602cb1e28d76a5398cec3fa21b0110385f501, 723d73b245843d4fff4c3f42e857c78c2b2d414e, 557ef547d49ff5e6026a4d39bdd3113bd81d7688, and 51a311eb97e91ce1aed3005cb71ccb2e30f8cce8. No additional mitigation is required beyond applying these official fixes.
Description
CVE-2026-89738 is a use-after-free vulnerability in the Linux kernel's at91_udc USB gadget driver. It occurs because a polled-VBUS timer and associated work are not properly drained before the USB device controller (udc) is freed during driver removal or probe failure. This can lead to dereferencing freed memory, causing potential system crashes or escalation of privileges. The issue affects Linux kernel version 2.6.36 and has been fixed in subsequent commits.
References
- git.kernel.org/stable/c/723d73b245843d4fff4c3f42e857c78c2b2d414e (opens in a new tab)
- git.kernel.org/stable/c/a2a602cb1e28d76a5398cec3fa21b0110385f501 (opens in a new tab)
- git.kernel.org/stable/c/51a311eb97e91ce1aed3005cb71ccb2e30f8cce8 (opens in a new tab)
- git.kernel.org/stable/c/557ef547d49ff5e6026a4d39bdd3113bd81d7688 (opens in a new tab)
- git.kernel.org/stable/c/c27d13ce4bab80fbdf6523928071b6c24b37606c (opens in a new tab)