CVE-2026-80838
In the Linux kernel, the following vulnerability has been resolved: vxlan: keep the last remote linked during FDB flush A non-nexthop FDB entry is expected to have at least one remote while it remains reachable through the FDB hash table. A filtered bulk flush violates this invariant when every remote matches: It unlinks the last remote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush() to destroy the parent FDB entry. An RCU reader can find the parent during this interval. first_remote_rcu() then applies list_entry_rcu() to the empty list head, producing an invalid remote pointer that the receive learning path can read from and write to. When a matching remote is the sole remaining remote, leave it linked and ask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps the remote attached while sending the deletion notification and removing the parent from the lookup structures.
Affected versions
Linux kernel versions
6.7
and later are affected. Fixed in
6.12.108,
6.18.49,
7.1.13,
7.2.3,
7.3
and their respective stable series.
References
5 totalFrequently asked questions
-
What is CVE-2026-80838?
CVE-2026-80838 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.7 onward and has been patched in 6.12.108, 6.18.49, 7.1.13 and others. CVE-2026-80838 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
-
Is there a patch available for CVE-2026-80838?
Yes. CVE-2026-80838 has been patched. Fixed versions include 6.12.108, 6.18.49, 7.1.13 and others. If you are running Linux kernel 6.7 or later up to the fix versions, apply the relevant patch for your kernel branch.
-
Is CVE-2026-80838 actively exploited?
No. CVE-2026-80838 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.