CVE-2024-40959: Linux kernel · xfrm6: check ip6_dst_idev() return value in xfrm6_get_saddr()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 4.4.0-1139.145 : update Linux kernel when convenient.
Data as of 28 Oct 2026, 11:01 UTC
- Patch
- Available – fixed in 4.4.0-1139.145, 4.15.0-1184.199~14.04.1, 4.4.0-262.296~14.04.1 +93
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 12 Jul 2024
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.
Patches and advisories
- ubuntu.com/security/notices/USN-6999-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7004-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7006-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7008-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7019-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=nobleOther 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 addressing this vulnerability is available and has been released in multiple Linux kernel versions including 4.4.0-1139.145 and 4.15.0-1184.199~14.04.1. Users and administrators should update their Linux kernel to one of the fixed versions to remediate this issue. No additional mitigation steps are required beyond applying the official kernel updates.
Description
CVE-2024-40959 is a vulnerability in the Linux kernel's IPv6 transform (xfrm6) subsystem. The issue arises because the function xfrm6_get_saddr does not properly check the return value of ip6_dst_idev(), which can be NULL. This can lead to a null pointer dereference and a kernel crash (denial of service). The flaw was reported by syzbot and affects multiple Linux kernel versions. Fixes have been released in several kernel versions.
References
- ubuntu.com/security/CVE-2024-40959 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-40959 (opens in a new tab)
- git.kernel.org/linus/d46401052c2d5614da8efea5788532f0401cb164 (opens in a new tab)
- git.kernel.org/stable/c/c71761292d4d002a8eccb57b86792c4e3b3eb3c7 (opens in a new tab)
- git.kernel.org/stable/c/caf0bec84c62fb1cf6f7c9f0e8c857c87f8adbc3 (opens in a new tab)
- git.kernel.org/stable/c/20427b85781aca0ad072851f6907a3d4b2fed8d1 (opens in a new tab)
- git.kernel.org/stable/c/9f30f1f1a51d91e19f5a09236bb0b59e6a07ad08 (opens in a new tab)
- git.kernel.org/stable/c/83c02fb2cc0afee5bb53cddf3f34f045f654ad6a (opens in a new tab)
- git.kernel.org/stable/c/f897d7171652fcfc76d042bfec798b010ee89e41 (opens in a new tab)
- git.kernel.org/stable/c/600a62b4232ac027f788c3ca395bc2333adeaacf (opens in a new tab)
- git.kernel.org/stable/c/d46401052c2d5614da8efea5788532f0401cb164 (opens in a new tab)
- ubuntu.com/security/notices/USN-6999-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7004-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7006-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7008-1 (opens in a new tab)