CVE-2026-43306: Linux kernel · bpf: crypto: Use the correct destructor kfunc type
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 26 Oct 2026, 13:47 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.
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 8 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
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 fix is available for this vulnerability. Users should apply the official kernel updates that include the corrected destructor kfunc type to resolve the issue. Since this is a kernel-level fix, upgrading to patched kernel versions is the recommended remediation.
Description
A vulnerability in the Linux kernel's BPF crypto subsystem related to the use of an incorrect destructor kfunc type has been resolved. With CONFIG_CFI enabled, the kernel enforces strict type matching for indirect function calls, and a type mismatch was causing internal errors during BPF self-tests. The issue was fixed by adding a stub function with the correct type as the destructor kfunc.
References
- ubuntu.com/security/CVE-2026-43306 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43306 (opens in a new tab)
- git.kernel.org/linus/b40a5d724f29fc2eed23ff353808a9aae616b48a (opens in a new tab)
- git.kernel.org/stable/c/3979a550fe06b370d73647f59cf462fa525c9ec4 (opens in a new tab)
- git.kernel.org/stable/c/4e3e57dbf46dad3498f8c4219ce2dba756875962 (opens in a new tab)
- git.kernel.org/stable/c/50d6fd69388cc7b05dce72f09080674dcede4ac9 (opens in a new tab)
- git.kernel.org/stable/c/b40a5d724f29fc2eed23ff353808a9aae616b48a (opens in a new tab)