CVE-2026-45897: Linux kernel · netfilter: nft_counter: serialize reset with spinlock
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
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.
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 27 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@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– |
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 that adds a global spinlock to serialize counter fetch and reset operations in the netfilter nft_counter component. Users should apply the vendor-provided patches or upgrade to fixed Linux kernel versions to remediate this issue. No alternative mitigations are indicated.
Description
A vulnerability in the Linux kernel's netfilter nft_counter component related to concurrent reset operations has been resolved by adding a global spinlock to serialize counter fetch and reset operations. This prevents concurrent dump-and-reset operations from causing counter underruns. The fix involves taking a global lock before fetching counter totals to avoid race conditions between parallel resets. The vulnerability affects specific Linux kernel versions listed and has a medium severity rating with a CVSS score of 5.5.
References
- ubuntu.com/security/CVE-2026-45897 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-45897 (opens in a new tab)
- git.kernel.org/linus/779c60a5190c42689534172f4b49e927c9959e4e (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-45897 (opens in a new tab)
- git.kernel.org/stable/c/0cdc6d5a26f2d1f7f15a43526841b679445c32e2 (opens in a new tab)
- git.kernel.org/stable/c/48cf7918d10c66cb6b05226fa3fa5daf0c891089 (opens in a new tab)
- git.kernel.org/stable/c/779c60a5190c42689534172f4b49e927c9959e4e (opens in a new tab)
- git.kernel.org/stable/c/cd968dcdec6aee79a2d399e4f6e0eca63c3b45e1 (opens in a new tab)