Bug 2521357 (CVE-2026-74625) - CVE-2026-74625 kernel: netfilter: bridge: release template ct on non-IP path
Summary: CVE-2026-74625 kernel: netfilter: bridge: release template ct on non-IP path
Keywords:
Status: NEW
Alias: CVE-2026-74625
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-22 15:41 UTC by OSIDB Bzimport
Modified: 2026-08-24 06:48 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2026-08-22 15:41:33 UTC
In the Linux kernel, the following vulnerability has been resolved:

netfilter: bridge: release template ct on non-IP path

A bridge nftables ct zone set rule can attach a conntrack template to
an skb before nf_ct_bridge_pre() sees it. For non-IPv4 and non-IPv6
EtherTypes, nf_ct_bridge_pre() currently overwrites skb->_nfct with
IP_CT_UNTRACKED without releasing the existing template reference.

That makes the per-cpu template, and any temporary templates allocated
for concurrent use, unreachable and leaks memory until the host runs out
of slab.

Reset the skb conntrack state before marking the frame untracked so the
existing template reference is dropped on the non-IP path.


Note You need to log in before you can comment on or make changes to this bug.