CVE-2026-80976
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.71%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.71% probability · 53th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS 0.7% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://git.kernel.org/stable/c/2b154e96fcb3f01fd42765c64e0a56820fbc16eb
- https://git.kernel.org/stable/c/96c74420ac92930a7e0f21770818544eee4a93d7
- https://git.kernel.org/stable/c/9ae92198c24d7dacd4070e2f34f6e1ed3a63061c
- https://git.kernel.org/stable/c/a0e2b0a3718f0cf9fb0ee41710b4a6348a7315c8
- https://git.kernel.org/stable/c/c73fb911e02b9a766c950bc9707f3e3a96ffd702
- https://git.kernel.org/stable/c/cfa186a0857a0f831dfca67b16bbc40ecfdf3280
- https://git.kernel.org/stable/c/d1f0d353358987ca87f21d8956e2d2854951130d
- https://git.kernel.org/stable/c/f967455fb2a5a2079b9eb5823e9ccf359174bf9f
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.