VulnerabilityPublished 27 May 2026Updated 6 Nov 2026

CVE-2026-45897: Linux kernel · netfilter: nft_counter: serialize reset with spinlock

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in e13194e60217db02c2e7202375d9e5951267d87b : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:05 UTC

Severity

Low

Rated Low by Threat Radar's AI analysis · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in e13194e60217db02c2e7202375d9e5951267d87b, de6601f1374fab124cd9276df6671f64d940ceb4, cd968dcdec6aee79a2d399e4f6e0eca63c3b45e1 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected >=6.1.107 <6.1.188 >=6.6.48 <6.6.157	Fixed in e13194e60217db02c2e7202375d9e5951267d87b de6601f1374fab124cd9276df6671f64d940ceb4 cd968dcdec6aee79a2d399e4f6e0eca63c3b45e1 779c60a5190c42689534172f4b49e927c9959e4e 48cf7918d10c66cb6b05226fa3fa5daf0c891089 6.6.157 6.1.188 0cdc6d5a26f2d1f7f15a43526841b679445c32e2
LinuxLinux	Affected =6.7	Fixed in–

AI-suggested

A fix is available and has been applied in Linux kernel versions 6.1.188, 6.6.157, and 6.7. Users and administrators should update to these or later kernel versions to remediate the vulnerability. No additional mitigation actions are indicated.

Description

CVE-2026-45897 is a vulnerability in the Linux kernel's netfilter nft_counter component. It involves a race condition during counter fetch and reset operations that could lead to underrunning counter values due to concurrent resets. The issue is addressed by adding a global static spinlock to serialize these operations, preventing concurrent resets from reading and subtracting the same counter values. The fix is implemented in Linux kernel versions 6.1.188, 6.6.157, and later.

Impact

The vulnerability could cause incorrect counter values due to concurrent resets underrunning the counters. This may affect the accuracy of netfilter counters but does not indicate direct security compromise or system stability issues. There is no evidence of exploitation in the wild. The impact is primarily on the correctness of counter data rather than on system security or availability.

Summary

This vulnerability in the Linux kernel's netfilter nft_counter arises from a lack of serialization when performing counter fetch and reset operations. Without proper locking, two parallel resets can read the same counter values and both subtract them, causing underrun errors. The resolution introduces a global static spinlock to serialize these operations, ensuring that only one reset can proceed at a time. This global lock simplifies the fix given the infrequency of resets, with a potential future optimization to per-network locks if performance bottlenecks occur. The vulnerability affects specific Linux kernel versions prior to 6.1.188, 6.6.157, and version 6.7, with fixes committed in those and related versions.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 16:05 UTC

Technical details

References

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