Answer in brief
CVE-2025-22021 records a Critical severity (CVSS 10.0) vulnerability in netfilter: socket: Lookup orig tuple for IPv6 SNAT. The current sources do not mark it as known exploited. The current feed maps 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 10.0. 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). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.14:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <6488b96a79a26e19100ad872622f04e93b638d7f || >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <58ab63d3ded2ca6141357a2b24eee8453d0f871d || >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <1ca2169cc19dca893c7aae6af122852097435d16 || >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <1ec43100f7123010730b7ddfc3d5c2eac19e70e7 || >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <5251041573850e5020cd447374e23010be698898 || >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <2bb139e483f8cbe488d19d8c1135ac3615e2668c || >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <41904cbb343d115931d6bf79aa2c815cac4ef72b || >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <221c27259324ec1404f028d4f5a0f2ae7f63ee23 || >=eb31628e37a0a4e01fffd79dcc7f815d2357f53a <932b32ffd7604fb00b5c57e239a3cc4d901ccf6e | 6488b96a79a26e19100ad872622f04e93b638d7f, 58ab63d3ded2ca6141357a2b24eee8453d0f871d, 1ca2169cc19dca893c7aae6af122852097435d16, 1ec43100f7123010730b7ddfc3d5c2eac19e70e7, 5251041573850e5020cd447374e23010be698898, 2bb139e483f8cbe488d19d8c1135ac3615e2668c, 41904cbb343d115931d6bf79aa2c815cac4ef72b, 221c27259324ec1404f028d4f5a0f2ae7f63ee23, 932b32ffd7604fb00b5c57e239a3cc4d901ccf6e |
| Linux/Linuxgeneric | 3.13 | Not reported |
Published upstream
Apr 16, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 15, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 5, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: socket: Lookup orig tuple for IPv6 SNAT nf_sk_lookup_slow_v4 does the conntrack lookup for IPv4 packets to restore the original 5-tuple in case of SNAT, to be able to find the right socket (if any). Then socket_match() can correctly check whether the socket was transparent. However, the IPv6 counterpart (nf_sk_lookup_slow_v6) lacks this conntrack lookup, making xt_socket fail to match on the socket when the packet was SNATed. Add the same logic to nf_sk_lookup_slow_v6. IPv6 SNAT is used in Kubernetes clusters for pod-to-world packets, as pods' addresses are in the fd00::/8 ULA subnet and need to be replaced with the node's external address. Cilium leverages Envoy to enforce L7 policies, and Envoy uses transparent sockets. Cilium inserts an iptables prerouting rule that matches on `-m socket --transparent` and redirects the packets to localhost, but it fails to match SNATed IPv6 packets due to that missing conntrack lookup.
Quoted source text, attributed separately from HOL analysis.