netfilter: nf_conntrack_sip: validate skb_dst() before accessing it

Summary

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.

Timeline

1. Aug 15, 2026, 5:54 AM UTCCVE published
2. Oct 16, 2026, 6:45 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Oct 16, 2026, 6:55 PM UTCRecord last updated

Affected versions

• Linux 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 Linux

  4.3

• KernelLinux

  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

References 8