CVE-2026-43009: Linux kernel · bpf: Fix incorrect pruning due to atomic fetch precision tracking
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-1035.38 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 6.8.0-1035.38, 7.0.0-1006.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 1 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 the Ubuntu to 6.8.0-1035.38 (linux-nvidia-tegra package) or 7.0.0-1006.6 (linux-nvidia package).
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 26.04 LTSlinux-nvidiapkg:deb/ubuntu/linux-nvidia?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– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
An official fix is available and should be applied. The vulnerability is resolved in Linux kernel versions 7.0.0-1006.6 and later. Users and administrators should update to a fixed kernel version to mitigate this issue.
Description
A vulnerability in the Linux kernel's BPF subsystem related to incorrect pruning due to atomic fetch precision tracking has been resolved. The issue arises because the backtracking logic did not properly handle atomic fetch instructions, causing the verifier to incorrectly consider different states equivalent and prune branches that should remain distinct. This could lead to incorrect verification of BPF programs. The fix extends the handling of atomic fetch instructions to correctly propagate precision information, preventing improper pruning.
References
- ubuntu.com/security/CVE-2026-43009 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43009 (opens in a new tab)
- git.kernel.org/linus/179ee84a89114b854ac2dd1d293633a7f6c8dac1 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-43009 (opens in a new tab)
- git.kernel.org/stable/c/179ee84a89114b854ac2dd1d293633a7f6c8dac1 (opens in a new tab)
- git.kernel.org/stable/c/7ffbe45b1d227e24659998a91cfd4c27af457e71 (opens in a new tab)
- git.kernel.org/stable/c/ea150ffa9fc9f78c5cf22e1f7b06b6d016b1017c (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)