CVE-2026-46172: ipv6: xfrm6: release dst on error in xfrm6_rcv_encap()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-28 · updated 2026-10-15

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: xfrm6: release dst on error in xfrm6_rcv_encap() xfrm6_rcv_encap() performs an IPv6 route lookup when the skb does not already have a dst attached. ip6_route_input_lookup() returns a referenced dst entry even when the lookup resolves to an error route. If dst->error is set, xfrm6_rcv_encap() drops the skb without attaching the dst to the skb and without releasing the reference returned by the lookup. Repeated packets hitting this path therefore leak dst entries. Release the dst before jumping to the drop path.

Affected products

Linux kernel: from 5.8 before 5.10.258; from 5.11 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.140; from 6.7 before 6.12.88; from 6.13 before 6.18.30 — fixed in 5.10.258, 5.15.209, 6.1.175, 6.12.88, 6.18.30, 6.6.140

How to fix

Upgrade to a fixed version: Linux kernel 5.10.258, 5.15.209, 6.1.175, 6.12.88. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-46172 or the next vulnerability affects your stack