Answer in brief
CVE-2026-80976 records a Critical severity (CVSS 9.8) vulnerability in seg6: reset IP6CB after IPv6 decapsulation. The current sources do not mark it as known exploited. The current feed maps 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 9.8. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <2b154e96fcb3f01fd42765c64e0a56820fbc16eb || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <cfa186a0857a0f831dfca67b16bbc40ecfdf3280 || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <c73fb911e02b9a766c950bc9707f3e3a96ffd702 || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <f967455fb2a5a2079b9eb5823e9ccf359174bf9f | 2b154e96fcb3f01fd42765c64e0a56820fbc16eb, cfa186a0857a0f831dfca67b16bbc40ecfdf3280, c73fb911e02b9a766c950bc9707f3e3a96ffd702, f967455fb2a5a2079b9eb5823e9ccf359174bf9f |
| Linux/Linuxgeneric | 4.14 | Not reported |
| Linux/Linuxgeneric | >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <d1f0d353358987ca87f21d8956e2d2854951130d || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <a0e2b0a3718f0cf9fb0ee41710b4a6348a7315c8 || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <9ae92198c24d7dacd4070e2f34f6e1ed3a63061c || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <96c74420ac92930a7e0f21770818544eee4a93d7 || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <2b154e96fcb3f01fd42765c64e0a56820fbc16eb || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <cfa186a0857a0f831dfca67b16bbc40ecfdf3280 || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <c73fb911e02b9a766c950bc9707f3e3a96ffd702 || >=d7a669dd2f8ba07a17423f4ad586dfc0379882f7 <f967455fb2a5a2079b9eb5823e9ccf359174bf9f | d1f0d353358987ca87f21d8956e2d2854951130d, a0e2b0a3718f0cf9fb0ee41710b4a6348a7315c8, 9ae92198c24d7dacd4070e2f34f6e1ed3a63061c, 96c74420ac92930a7e0f21770818544eee4a93d7, 2b154e96fcb3f01fd42765c64e0a56820fbc16eb, cfa186a0857a0f831dfca67b16bbc40ecfdf3280, c73fb911e02b9a766c950bc9707f3e3a96ffd702, f967455fb2a5a2079b9eb5823e9ccf359174bf9f |
Published upstream
Sep 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 19, 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: 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.
Quoted source text, attributed separately from HOL analysis.