CVEvulnerability
CVE-2026-98096
7.4 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-09-25
- Last modified
- 2026-10-28
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.4 HIGH — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H
- Weaknesses
- CWE-787
Description
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.
Affected configurations
• linux linux kernel (>= 4.10 < 5.10.271)
• linux linux kernel (>= 5.11 < 5.15.222)
• linux linux kernel (>= 6.0 < 6.1.189)
• linux linux kernel (>= 6.2 < 6.6.158)
• linux linux kernel (>= 6.7 < 6.12.111)
• linux linux kernel (>= 6.13 < 6.18.53)
• linux linux kernel (>= 6.19 < 7.2.7)
• linux linux kernel 7.3
Related
Weakness · CWE (1)
- CWE-787 Out-of-bounds Write weakness
References
- https://git.kernel.org/stable/c/3ad7dca5e03bd64c65983a19734337512fd75491 Patch
- https://git.kernel.org/stable/c/8f44d4160bcdb3136a9145a4b9c7816382976925 Patch
- https://git.kernel.org/stable/c/975b5b067f525a1b1338c4a3bee1c46545801518 Patch
- https://git.kernel.org/stable/c/97b21ef57dfabbff660a4672c9fef7edfb720f47 Patch
- https://git.kernel.org/stable/c/9cfbe2c381ab6d00a08e7a5b6028865adfb4e1bc Patch
- https://git.kernel.org/stable/c/af08f62b5a5a446d6134a92d86771d3d12e0e3da Patch
- https://git.kernel.org/stable/c/ce4c8beedc19aceeab0e7bdc6f34394fb158c47c Patch
- https://git.kernel.org/stable/c/f463c4786cf27376de7dfc0833a12e924a98f698 Patch