Race condition in Linux kernel bridge CFM peer_mep deletion
CVE-2026-23393 is a race condition in the Linux kernel bridge Connectivity Fault Management (CFM) code during peer MEP deletion. When a peer MEP is deleted, the kernel called cancel_delayed_work_sync() on ccm_rx_dwork before freeing the object. However, br_cfm_frame_rx() executes in softirq context under rcu_read_lock() without RTNL and can reschedule ccm_rx_dwork via ccm_rx_timer_start() after cancel_delayed_work_sync() returns but before hlist_del_rcu() and kfree_rcu() complete. This creates a window where delayed work can later run in ccm_rx_work_expired() against a freed peer_mep object, resulting in a use-after-free condition. The fix replaces cancel_delayed_work_sync() with disable_delayed_work_sync() in both peer MEP deletion paths so subsequent queue_delayed_work() attempts from br_cfm_frame_rx() are rejected during deletion. The cc_peer_disable() helper intentionally retains cancel_delayed_work_sync() because it is also used for the CC enable/disable toggle path where rescheduling must remain possible.
Are you exposed to this one?
Mallory correlates every CVE against your assets, your vendors, and active adversary campaigns. Know which vulnerabilities matter for you, not just which ones are loud.
Impact, mitigation & remediation
What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.
Impact
What an attacker gets, and what they’ve been doing with it.
Mitigation
If you can’t patch tonight, do this now.
Remediation
Patch, then assume compromise.
Exploits
No public exploits tracked yet. Mallory keeps watching.
No public exploit code observed for this vulnerability.
Affected products & vendors
Products and vendors Mallory has correlated with this vulnerability. Open in Mallory to drill down to specific CPE configurations and version ranges.
Vendor-confirmed product mapping. Mallory continuously reconciles this list against your asset inventory.
Recent activity
8 sources tracked across advisories and community write-ups. News coverage will land here when it surfaces.
No news coverage yet. Advisories and community discussion only.
The version that knows your environment.
Query your assets running an affected version, and investigate the blast radius.
Every observed campaign linking this CVE to a named adversary.
Malware families riding this exploit, with evidence and IOCs.
YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.
Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.