What’s Vulnerable › Vulnerabilities

CVE-2026-72253: netfilter: nf_conntrack_sip: validate skb_dst() before accessing it

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-08-15 · updated 2026-10-16

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.

Affected products

• Linux kernel: 4.3 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

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

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