Answer in brief
CVE-2026-89564 records a High severity (CVSS 7.8) vulnerability in ip: orphan prefetched skbs before multicast forwarding. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <f1281d4b99089fbaf0d3579bba62a814ebb4de4d || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <e36ce6e78fe3fc3c071a26750783b7ba081ce10d | a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce, f1281d4b99089fbaf0d3579bba62a814ebb4de4d, e36ce6e78fe3fc3c071a26750783b7ba081ce10d |
| Linux/Linuxgeneric | 5.7 | Not reported |
| Linux/Linuxgeneric | >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <e62aef7d6a5b27569bf540bbe11a9482117ff588 || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <f1281d4b99089fbaf0d3579bba62a814ebb4de4d || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <e36ce6e78fe3fc3c071a26750783b7ba081ce10d | e62aef7d6a5b27569bf540bbe11a9482117ff588, a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce, f1281d4b99089fbaf0d3579bba62a814ebb4de4d, e36ce6e78fe3fc3c071a26750783b7ba081ce10d |
| Linux/Linuxgeneric | >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <882212d317a7c16ab70d20656f6b1c42abada9f6 || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <e62aef7d6a5b27569bf540bbe11a9482117ff588 || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <f1281d4b99089fbaf0d3579bba62a814ebb4de4d || >=cf7fbe660f2dbd738ab58aea8e9b0ca6ad232449 <e36ce6e78fe3fc3c071a26750783b7ba081ce10d | 882212d317a7c16ab70d20656f6b1c42abada9f6, e62aef7d6a5b27569bf540bbe11a9482117ff588, a8af6fbac895f057c4b8ff8a2e3fb4c5827fe4ce, f1281d4b99089fbaf0d3579bba62a814ebb4de4d, e36ce6e78fe3fc3c071a26750783b7ba081ce10d |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 11, 2026
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.
Quoted source text, attributed separately from HOL analysis.