CVE-2026-23124: Linux kernel · ipv6: annotate data-race in ndisc_router_discovery()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1105.112~20.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1105.112~20.04.1, 5.15.0-1110.119~20.04.1, 5.15.0-1106.115~20.04.1 +59
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 14 Feb 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@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?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 by updating to the fixed Linux kernel versions as provided by the vendor. The Ubuntu advisory confirms that the issue is resolved in updated linux-nvidia-tegra kernel packages. After applying the update, a system reboot is required. No additional mitigation steps are necessary beyond applying the official fix.
Description
A data race vulnerability was identified and resolved in the Linux kernel's IPv6 implementation, specifically in the ndisc_router_discovery() function. The issue involved unsynchronized read and write access to the in6_dev->ra_mtu variable, which could lead to kernel instability or crashes. The vulnerability has been addressed by adding appropriate memory access annotations (READ_ONCE()/WRITE_ONCE()) to document and prevent the race condition. This fix is included in updated Linux kernel packages.
References
- ubuntu.com/security/CVE-2026-23124 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-23124 (opens in a new tab)
- git.kernel.org/linus/9a063f96d87efc3a6cc667f8de096a3d38d74bb5 (opens in a new tab)
- git.kernel.org/stable/c/2619499169fb1c2ac4974b0f2d87767fb543582b (opens in a new tab)
- git.kernel.org/stable/c/2a2b9d25f801afecf2f83cacce98afa8fd73e3c9 (opens in a new tab)
- git.kernel.org/stable/c/4630897eb1a039b5d7b737b8dc9521d9d4b568b5 (opens in a new tab)
- git.kernel.org/stable/c/9a063f96d87efc3a6cc667f8de096a3d38d74bb5 (opens in a new tab)
- git.kernel.org/stable/c/e3c1040252e598f7b4e33a42dc7c38519bc22428 (opens in a new tab)
- git.kernel.org/stable/c/fad8f4ff7928f4d52a062ffdcffa484989c79c47 (opens in a new tab)
- ubuntu.com/security/notices/USN-8162-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8180-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8180-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8186-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8187-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8188-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8180-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8180-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8180-5 (opens in a new tab)
- ubuntu.com/security/notices/USN-8243-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8180-6 (opens in a new tab)