CVE-2026-72389
In the Linux kernel, the following vulnerability has been resolved: bridge: stp: Fix a potential use-after-free when deleting a bridge The three STP timers are not supposed to be armed while the bridge is administratively down.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.16%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: bridge: stp: Fix a potential use-after-free when deleting a bridge The three STP timers are not supposed to be armed while the bridge is administratively down. They are synchronously deactivated when the bridge is put administratively down and the various call sites check for 'IFF_UP' before arming them. This check is missing from br_topology_change_detection() and it is possible to engineer a situation in which the topology change timer is armed while the bridge is administratively down, resulting in a use-after-free [1] when the bridge is deleted. Fix by adding the missing check and for good measures synchronously shutdown the three timers when the bridge is deleted. [1] ODEBUG: free active (active state 0) object: ffff88811662b9b0 object type: timer_list hint: br_topology_change_timer_expired (net/bridge/br_stp_timer.c:120) WARNING: lib/debugobjects.c:629 at debug_print_object+0x1bc/0x450, CPU#9: ip/359
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.16% probability · 6th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/297a747f59bff6573196d7236178144d66524e68
- https://git.kernel.org/stable/c/2a00517db8de4be7df3d483b215c5544fb30a191
- https://git.kernel.org/stable/c/39283907a25e5caf0f2bd2947f6e56644b01e2b7
- https://git.kernel.org/stable/c/40cbfa3a28e0919469d1b086629bb3ce38a83593
- https://git.kernel.org/stable/c/4c40eec06eeac37c58e47a6058eb32901218d5d4
- https://git.kernel.org/stable/c/b4b3458ef88df4798632619f018791d4344bcd92
- https://git.kernel.org/stable/c/c86579b0a2d201792bcb59316629f4ba4758cfc8
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.