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.

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Advisories
Source ID Title
Debian DSA Debian DSA DSA-6528-1 linux security update
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Fri, 25 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-119

Fri, 25 Sep 2026 21:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-120
CWE-125

Fri, 25 Sep 2026 16:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-120
CWE-125

Fri, 25 Sep 2026 15:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H'}


Fri, 25 Sep 2026 10:30:00 +0000

Type Values Removed Values Added
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.
Title ipv6: sr: restore network header before routing and forwarding
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-09-25T14:42:04.399Z

Reserved: 2026-09-25T10:19:56.076Z

Link: CVE-2026-98096

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-25T11:17:39.373

Modified: 2026-09-30T14:10:59.253

Link: CVE-2026-98096

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-26T18:00:12Z

Weaknesses