CVE-2026-43216: Linux kernel · net: Drop the lock in skb_may_tx_timestamp()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.15.0-1117.124~20.04.1 : 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 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +41
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 6 May 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 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde@7.0.0-1008.8?arch=source&distro=resoluteOther threats | 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– |
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-aws kernel versions. The vendor advisory confirms that this issue has been fixed. Users should update to the fixed kernel versions to mitigate this vulnerability.
Description
A vulnerability in the Linux kernel's networking code (CVE-2026-43216) involved improper locking in the skb_may_tx_timestamp() function, which could cause a deadlock when the lock is taken in an interrupt context. This issue has been resolved by removing the problematic lock and using safe pointer access methods. The vulnerability affects specific linux-aws kernel versions and has a medium severity rating with a CVSS score of 5.5.
References
- ubuntu.com/security/CVE-2026-43216 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43216 (opens in a new tab)
- git.kernel.org/linus/983512f3a87fd8dc4c94dfa6b596b6e57df5aad7 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-43216 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)
- git.kernel.org/stable/c/3709d73ace37e9aaebb688f5a5cf706d74350b64 (opens in a new tab)
- git.kernel.org/stable/c/4839cbda8f13e99ce2bb3b593f5cc3288415684b (opens in a new tab)
- git.kernel.org/stable/c/983512f3a87fd8dc4c94dfa6b596b6e57df5aad7 (opens in a new tab)
- git.kernel.org/stable/c/c770217044d9cbe16a1f7c385cf080ed06a2fc04 (opens in a new tab)
- git.kernel.org/stable/c/cd2463ec60f0d6e460078037c86f9d0947ee1ff6 (opens in a new tab)
- git.kernel.org/stable/c/cf7599116c4c0082fd25cb1bf0254631da0ed06e (opens in a new tab)
- git.kernel.org/stable/c/e4c6efb3b70ff87f1df99efce2f8893717695718 (opens in a new tab)
- git.kernel.org/stable/c/f3e4cceafad27c9363c33622732f86722846ec6f (opens in a new tab)
- ubuntu.com/security/notices/USN-8876-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8878-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8879-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8877-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8875-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8917-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8918-1 (opens in a new tab)