CVE-2026-97615 net: bridge: use option bits for CFM/MRP frame handlers
A memory corruption vulnerability in the Linux kernel bridge module allows attackers to corrupt list states, potentially causing denial of service or code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97615?
CVE-2026-97615 is a memory corruption vulnerability in Linux, published on 25 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
net: bridge: use option bits for CFM/MRP frame handlers
CFM and MRP register a global br_frame_type whose hlist_node is linked into the per-bridge frame_type_list when the first MEP/MRP instance is created. Enabling the protocol on multiple bridges therefore inserts the same node into multiple lists. Unregistering it on one bridge then corrupts list state belonging to another.
These handlers can only be installed once per bridge, and they are uncommon. Track their per-bridge enable state with net_bridge option bits, which already live on the Rx hot cache line, and dispatch the matching handler directly from the receive path. Check both bits together first as an unlikely case.
Remove the generic frame_type_list and br_frame_type helpers, which have had no other users since CFM and MRP were added. That shrinks struct net_bridge by 8 bytes and drops the list walk from the fast path. When neither protocol is compiled in, BR_CFM_MRP_OPTS is 0 and the compiler prunes the branch.
Which versions are affected by CVE-2026-97615?
How do I fix CVE-2026-97615?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-97615 being exploited?
There is no known exploitation of CVE-2026-97615 in the wild and no public exploit code.
Sources
Also known as AZL-104274, BELL-CVE-2026-97615, DEBIAN-CVE-2026-97615, GHSA-jx7q-xjrp-x794, UBUNTU-CVE-2026-97615.