In the Linux kernel, the following vulnerability has been resolved:
seg6: validate SRH length before reading fixed fields
seg6_validate_srh() reads fixed SRH fields such as srh->type and
srh->hdrlen before checking that the supplied length covers the fixed
struct ipv6_sr_hdr fields.
The BPF SEG6 encap path reaches this with a BPF program-supplied pointer
and length: bpf_lwt_push_encap() and the SEG6 local BPF END_B6 and
END_B6_ENCAP actions call bpf_push_seg6_encap(), which forwards the
length to seg6_validate_srh() with no minimum-size guard. A 2-byte SEG6
encap header can therefore make the validator read srh->type at offset 2
beyond the caller-supplied buffer.
Reject lengths shorter than the fixed SRH at the top of
seg6_validate_srh(), before any field is read. This fixes the BPF helper
path and keeps the common validator robust.
References
Configurations
No configuration.
History
No history.
Information
Published : 2026-08-15 06:22
Updated : 2026-08-17 06:19
NVD link : CVE-2026-72400
Mitre link : CVE-2026-72400
CVE.ORG link : CVE-2026-72400
JSON object : View
Products Affected
No product.
CWE
No CWE.
