CVE-2026-80976

CVE CVE-2026-80976EUVD EUVD-2026-76299Published 2026-09-11T19:42:38.000ZLast changed 2026-09-14T11:59:21.000ZCVSS 9.8

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: seg6: reset IP6CB after IPv6 decapsulation decap_and_validate() pulls the outer SRv6 headers and makes the inner packet the skb network header. The IPv6 control block still contains values collected while parsing the outer packet, including nhoff and extension-header flags. End.DX6 and End.DT6 route the inner IPv6 packet directly to the IPv6 input path. An unprivileged user can reach End.DT6 from a user and net namespace by installing a local SID and injecting an outer packet with Hop-by-Hop and Destination Options headers followed by an SRH and a minimal inner IPv6 packet. The outer extension headers leave a large nhoff in IP6CB. After decapsulation, ip6_protocol_deliver_rcu() uses that stale offset on the inner packet and reads beyond the skb head. KASAN reports: BUG: KASAN: slab-out-of-bounds in ip6_protocol_deliver_rcu ip6_protocol_deliver_rcu+0x1118/0x1450 ip6_input_finish+0x11b/0x240 seg6_local_input_core+0xed/0x2e0 lwtunnel_input+0x1e9/0x4e0 ipv6_rthdr_rcv+0x525f/0x6c50 ip6_protocol_deliver_rcu+0xcb7/0x1450 Before clearing IP6CB for an inner IPv6 packet, save its incoming interface index and L3 slave state. Restore both after the clear and set nhoff to the inner IPv6 base-header nexthdr field. Use IP6CB(skb)->iif rather than skb->skb_iif because VRF processing can replace skb_iif with the L3 master while IP6CB keeps the receiving interface. Preserve IP6SKB_L3SLAVE for the same reason.

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: 0; d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <c73fb911e02b9a766c950bc9707f3e3a96ffd702; d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <f967455fb2a5a2079b9eb5823e9ccf359174bf9f; patch: 6.1.188; d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <cfa186a0857a0f831dfca67b16bbc40ecfdf3280; patch: 5.15.221; d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <2b154e96fcb3f01fd42765c64e0a56820fbc16eb; patch: 7.2.4; patch: 5.10.270; patch: 7.3-rc1; d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <d1f0d353358987ca87f21d8956e2d2854951130d; 4.14; patch: 6.12.109; patch: 6.18.50; d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <96c74420ac92930a7e0f21770818544eee4a93d7; patch: 6.6.157; d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <9ae92198c24d7dacd4070e2f34f6e1ed3a63061c; d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <a0e2b0a3718f0cf9fb0ee41710b4a6348a7315c8

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

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

Patchlage reports hits and suspected hits. About everything else this system says nothing — neither this page nor the situation report ever claims that an estate is safe.