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VulnerabilityPublished Updated

CVE-2026-89738: Linux kernel · usb: gadget: at91_udc: drain polled-VBUS timer/work before udc is freed

Affects Linux kernelSource CVE Database V5

0

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

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 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:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 11 Sep 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
  • ≥ 4037242c4f5ff77afe61bf07ca1e8a99490219e5, < c27d13ce4bab80fbdf6523928071b6c24b37606c
Fixed in
  • c27d13ce4bab80fbdf6523928071b6c24b37606c
LinuxLinuxAffected
  • ≥ 4037242c4f5ff77afe61bf07ca1e8a99490219e5, < a2a602cb1e28d76a5398cec3fa21b0110385f501
Fixed in
  • a2a602cb1e28d76a5398cec3fa21b0110385f501
LinuxLinuxAffected
  • ≥ 4037242c4f5ff77afe61bf07ca1e8a99490219e5, < 723d73b245843d4fff4c3f42e857c78c2b2d414e
Fixed in
  • 723d73b245843d4fff4c3f42e857c78c2b2d414e
LinuxLinuxAffected
  • ≥ 4037242c4f5ff77afe61bf07ca1e8a99490219e5, < 557ef547d49ff5e6026a4d39bdd3113bd81d7688
Fixed in
  • 557ef547d49ff5e6026a4d39bdd3113bd81d7688
LinuxLinuxAffected
  • ≥ 4037242c4f5ff77afe61bf07ca1e8a99490219e5, < 51a311eb97e91ce1aed3005cb71ccb2e30f8cce8
Fixed in
  • 51a311eb97e91ce1aed3005cb71ccb2e30f8cce8
LinuxLinuxAffected
  • =2.6.36
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

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