CVE-2026-23393

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Source
https://cve.org/CVERecord?id=CVE-2026-23393
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23393.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2026-23393
Downstream
Related
Published
2026-03-25T10:33:17Z
Modified
2026-08-12T03:30:51Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
bridge: cfm: Fix race condition in peer_mep deletion
Details

In the Linux kernel, the following vulnerability has been resolved:

bridge: cfm: Fix race condition in peer_mep deletion

When a peer MEP is being deleted, cancel_delayed_work_sync() is called on ccm_rx_dwork before freeing. However, br_cfm_frame_rx() runs in softirq context under rcu_read_lock (without RTNL) and can re-schedule ccm_rx_dwork via ccm_rx_timer_start() between cancel_delayed_work_sync() returning and kfree_rcu() being called.

The following is a simple race scenario:

       cpu0                                     cpu1

mep_delete_implementation() cancel_delayed_work_sync(ccm_rx_dwork); br_cfm_frame_rx() // peer_mep still in hlist if (peer_mep->ccm_defect) ccm_rx_timer_start() queue_delayed_work(ccm_rx_dwork) hlist_del_rcu(&peer_mep->head); kfree_rcu(peer_mep, rcu); ccm_rx_work_expired() // on freed peer_mep

To prevent this, cancel_delayed_work_sync() is replaced with disable_delayed_work_sync() in both peer MEP deletion paths, so that subsequent queue_delayed_work() calls from br_cfm_frame_rx() are silently rejected.

The cc_peer_disable() helper retains cancel_delayed_work_sync() because it is also used for the CC enable/disable toggle path where the work must remain re-schedulable.

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23393.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
dc32cbb3dbd7da38c700d6e0fc6354df24920525
Fixed
e89dbd2736a45f0507949af4748cbbf3ff793146
Fixed
d8f35767bacb3c7769d470a41cf161e3f3c07e70
Fixed
1fd81151f65927fd9edb8ecd12ad45527dbbe5ab
Fixed
3715a00855316066cdda69d43648336367422127

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23393.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
6.12.78
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.18.20
Type
ECOSYSTEM
Events
Introduced
6.19.0
Fixed
6.19.10

Database specific

source 
"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-23393.json"