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CVE-2026-98096

HIGH severity · CVSS 7.4 · Out-of-bounds write
7.4CVSS HIGH

Summary

In the Linux kernel, the following vulnerability has been resolved: ipv6: sr: restore network header before routing and forwarding ipv6_srh_rcv() runs with skb->data at the Segment Routing Header (SRH) while skb_network_header() points at the IPv6 header. When segments_left > 0, ipv6_srh_rcv() previously restored the skb->data position by pushing sizeof(struct ipv6hdr), assuming the SRH immediately followed the fixed IPv6 header. If another extension header (such as a Hop-by-Hop options header) precedes the SRH, skb_network_offset() remained negative. This led to two problems: 1. During ip6_route_input(), fib6_rules_early_flow_dissect() invokes __skb_flow_dissect() which passes the negative skb_network_offset() to flow dissection, breaking BPF and C flow dissector logic. 2. If forwarded via ip6_forward() or redirected via act_mirred, downstream handlers (like sch_fragment() or neighbour output) pass the negative offset as an unsigned length, triggering OOB memcpy or buffer overflows. Fix this by pushing -skb_network_offset(skb) before routing, ensuring skb_network_offset(skb) is 0 for route lookup / flow dissection as well as downstream forwarding. On the loopback path, pull skb_transport_offset(skb) to restore skb->data to the SRH before looping back.

Impact & exploitability

Attack vectorNetwork
Attack complexityHigh
Privileges requiredNone
User interactionNone
Confidentiality impactNone
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)1%

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H

Affected products we track (1)

Linux Kernel

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/3ad7dca5e03bd64c65983a19734337512fd75491 ↗

Additional information