CVE-2026-89564

CVE CVE-2026-89564EUVD EUVD-2026-76475Published 2026-09-11T19:44:35.000ZLast changed 2026-09-13T06:31:05.000ZCVSS 7.8

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: ip: orphan prefetched skbs before multicast forwarding IPv4 and IPv6 input preserve an skb->sk association installed by bpf_sk_assign() so that local delivery can use the selected socket under RCU. Both address families can also prefetch a socket in UDP early demux. In both paths (BPF and UDP early demux) a reference is not guaranteed to be held on the socket. When a multicast packet is not locally deliverable, IPv6 hands the original skb to ip6_mr_input(). IPv4's ip_mr_input() similarly keeps the original skb when local delivery is not needed. Either path can put the skb on an unresolved multicast route queue or forward it after the receive-side RCU section ends. After the prefetched socket is destroyed, a later skb free invokes sock_pfree() and dereferences the stale skb->sk. Orphan the skb before each non-local multicast forwarding path. Local delivery retains the original skb; the existing skb_clone() calls provide multicast forwarding with a socket-free clone.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux patch: 7.2.4; patch: 7.3-rc1; cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce; patch: 0; 5.7; cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <f1281d4b99089fbaf0d3579bba62a814ebb4de4d; patch: 6.18.50; cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <e36ce6e78fe3fc3c071a26750783b7ba081ce10d

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

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Linux — Linux

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