bridge: stp: Fix a potential use-after-free when deleting a bridge
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
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
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet |
| Red Hat Enterprise Linux 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
Timeline
- 2026-10-02 Threatist record created from CVE-2026-72389
- 2026-10-03 Alias added: GHSA-7jq5-5rp7-v6gf
- 2026-10-16 CISA SSVC decision points changed
References
Other 7
- https://git.kernel.org/stable/c/c86579b0a2d201792bcb59316629f4ba4758cfc8
- https://git.kernel.org/stable/c/297a747f59bff6573196d7236178144d66524e68
- https://git.kernel.org/stable/c/4c40eec06eeac37c58e47a6058eb32901218d5d4
- https://git.kernel.org/stable/c/39283907a25e5caf0f2bd2947f6e56644b01e2b7
- https://git.kernel.org/stable/c/b4b3458ef88df4798632619f018791d4344bcd92
- https://git.kernel.org/stable/c/40cbfa3a28e0919469d1b086629bb3ce38a83593
- https://git.kernel.org/stable/c/2a00517db8de4be7df3d483b215c5544fb30a191
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Sources
- CVE-2026-72389 · CVE Program
- CVE-2026-72389 · NVD
- FIRST EPSS
- GHSA-7jq5-5rp7-v6gf · GitHub Advisory Database · CC BY 4.0
- CVE-2026-72389 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences