CVE-2026-23281: Linux kernel · wifi: libertas: fix use-after-free in lbs_free_adapter()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1112.119~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 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.
- Patch
- Available – fixed in 5.15.0-1112.119~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2 +63
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 25 Mar 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 |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle?arch=source&distro=questingOther 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 patch is available and should be applied to affected Linux kernel versions. The fix replaces timer_delete() calls with timer_delete_sync() in the libertas wifi driver to ensure timer callbacks complete before memory is freed. Users should update to patched kernel versions as per vendor advisories such as Ubuntu Security Notice USN-8567-1. No additional mitigations are specified or required beyond applying the official fix.
Description
A use-after-free vulnerability in the Linux kernel's libertas wifi driver was resolved. The issue arises because the lbs_free_adapter() function uses timer_delete() which does not wait for running timer callbacks to complete before freeing memory. This can lead to timer callbacks accessing freed memory, causing use-after-free violations. The flaw was introduced in a commit that used del_timer() instead of del_timer_sync() in the cleanup path. The vulnerability affects specific Linux kernel versions and has a CVSS score of 7.8. A patch is available to fix this issue by replacing timer_delete() with timer_delete_sync().
References
- ubuntu.com/security/CVE-2026-23281 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23281 (opens in a new tab)
- git.kernel.org/linus/03cc8f90d0537fcd4985c3319b4fafbf2e3fb1f0 (opens in a new tab)
- git.kernel.org/stable/c/03cc8f90d0537fcd4985c3319b4fafbf2e3fb1f0 (opens in a new tab)
- git.kernel.org/stable/c/3c5c818c78b03a1725f3dcd566865c77b48dd3a6 (opens in a new tab)
- git.kernel.org/stable/c/3f9dec4a6d95d7f1f5e9e9dfdfa173c053bba8dc (opens in a new tab)
- git.kernel.org/stable/c/a9f55b14486426d907459bced5825a25063bd922 (opens in a new tab)
- git.kernel.org/stable/c/d0155fe68f31b339961cf2d4f92937d57e9384e6 (opens in a new tab)
- git.kernel.org/stable/c/ed7d30f90b77f73a47498686ede83f622b7e4f0d (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)