CVE-2026-23279: Linux kernel · wifi: mac80211: fix NULL pointer dereference in mesh_rx_csa_frame()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1112.119~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 3% 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:N/I:N/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 adds a NULL check for the mesh_chansw_params_ie element to prevent the NULL pointer dereference. Systems running vulnerable kernel versions should upgrade to a patched kernel as provided by their vendor. No additional mitigations are specified or required beyond applying the official fix.
Description
A NULL pointer dereference vulnerability in the Linux kernel's mac80211 wifi subsystem was fixed. The flaw occurs in the mesh_rx_csa_frame() function where an optional element (mesh_chansw_params_ie) is dereferenced without a NULL check, leading to a kernel crash. A remote mesh peer can trigger this by sending a crafted channel switch action frame omitting this element. The issue affects kernels since version 3.13 (2014) and requires only open mesh peering for exploitation. A patch is available to add the necessary NULL check.
References
- ubuntu.com/security/CVE-2026-23279 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23279 (opens in a new tab)
- git.kernel.org/linus/017c1792525064a723971f0216e6ef86a8c7af11 (opens in a new tab)
- git.kernel.org/stable/c/017c1792525064a723971f0216e6ef86a8c7af11 (opens in a new tab)
- git.kernel.org/stable/c/22a9adea7e26d236406edc0ea00b54351dd56b9c (opens in a new tab)
- git.kernel.org/stable/c/2b5f282b1b7241ef624c3399a1cdff0bb1a3eeab (opens in a new tab)
- git.kernel.org/stable/c/be8b82c567fda86f2cbb43b7208825125bb31421 (opens in a new tab)
- git.kernel.org/stable/c/cc6d5a3c0a854aeae00915fc5386570c86029c60 (opens in a new tab)
- git.kernel.org/stable/c/f5d8af683410a8c82e48b51291915bd612523d9a (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)