Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_inner: Fix IPv6 inner_thoff desync In nft_inner_parse_l2l3(), when processing inner IPv6 packets, ipv6_find_hdr() correctly computes the transport header offset traversing all extension headers, but the result is immediately overwritten with nhoff + sizeof(_ip6h) (40 bytes), which only accounts for the IPv6 base header. This creates a desync between inner_thoff (wrong — points to extension header start) and l4proto (correct — e.g., IPPROTO_TCP), enabling transport header forgery and potential firewall bypass. This issue affects stable versions from Linux 6.2. For comparison, the normal (non-inner) IPv6 path correctly preserves ipv6_find_hdr()'s result. Removing the incorrect overwrite ensures that ipv6_find_hdr()'s calculated transport header offset is preserved, thereby fixing the desynchronization.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 3a07327d10a09379315c844c63f27941f5081e0a before c161ad9157f5a0429b5ff94d9770faf3bf48d273; affected 3a07327d10a09379315c844c63f27941f5081e0a before 870d59e2cf218e7418491e26bad768cb16654582; affected 3a07327d10a09379315c844c63f27941f5081e0a before 689bbf48c1f45130086ae1c46ab83ea4c753c601; affected 3a07327d10a09379315c844c63f27941f5081e0a before d0f98a3617f6ae5b1e95cde1e68e7ead4a1279ce; affected 3a07327d10a09379315c844c63f27941f5081e0a before b6a91f68ebfed9c38e0e9150f58a9b85da07181c |
| Linux / Linux | affected 6.2; unaffected 0 before 6.2; unaffected 6.6.142 through 6.6.*; unaffected 6.12.92 through 6.12.*; unaffected 6.18.34 through 6.18.*; unaffected 7.0.11 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/c161ad9157f5a0429b5ff94d9770faf3bf48d273
- https://git.kernel.org/stable/c/870d59e2cf218e7418491e26bad768cb16654582
- https://git.kernel.org/stable/c/689bbf48c1f45130086ae1c46ab83ea4c753c601
- https://git.kernel.org/stable/c/d0f98a3617f6ae5b1e95cde1e68e7ead4a1279ce
- https://git.kernel.org/stable/c/b6a91f68ebfed9c38e0e9150f58a9b85da07181c
ADP enrichment
A flaw was found in the Linux kernel's netfilter subsystem, specifically within the nft_inner module. This vulnerability arises from an incorrect handling of IPv6 inner packet processing, where the transport header offset (inner_thoff) becomes desynchronized from the Layer 4 protocol (l4proto). A remote attacker could exploit this desynchronization to perform transport header forgery, potentially leading to a firewall bypass and allowing unauthorized network access.
- https://access.redhat.com/security/cve/CVE-2026-46244
- https://bugzilla.redhat.com/show_bug.cgi?id=2484451
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46244.json
- https://access.redhat.com/errata/RHSA-2026:33215
- https://access.redhat.com/errata/RHSA-2026:34911
- https://access.redhat.com/errata/RHSA-2026:34443
- https://access.redhat.com/errata/RHSA-2026:34094
- https://access.redhat.com/errata/RHSA-2026:36018
- https://access.redhat.com/errata/RHSA-2026:55618
- https://access.redhat.com/errata/RHSA-2026:56225
- https://access.redhat.com/errata/RHSA-2026:55763
No English description supplied.
No references supplied.