CVE-2026-68116: Linux kernel · vxlan: mdb: Fix source list corruption on a failed replace
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.9 High · fixed in 7.0.0-38.38~24.04.4 : patch Linux kernel soon.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 1% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-38.38~24.04.4, 6.8.0-1036.39, 7.0.0-38.38 +12
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:HExploitation evidence
Disclosed: evidence found.
CVE published 10 Aug 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: vxlan: mdb: Fix source list corruption on a failed replace When replacing the source list of an MDB remote entry, all existing sources are first marked for deletion and vxlan_mdb_remote_srcs_add() is then called to add the new source list. Sources present in the new list have their deletion mark cleared, and any sources left marked afterwards are removed. If vxlan_mdb_remote_srcs_add() fails partway through, its error path deletes all entries on the remote's source list. That rollback is only correct for its other caller, vxlan_mdb_remote_add(), where the remote was just allocated and the list contains solely entries added during the call. On the replace path the list also holds pre-existing sources, so a failed replace tears them down together with their (S, G) forwarding entries instead of leaving the entry unchanged. This is reachable from an existing (*, G) remote. An EXCLUDE filter that loses sources starts forwarding traffic that should be blocked, while an INCLUDE filter that loses sources drops traffic that should be forwarded. Mark entries created during the current pass with a new VXLAN_SGRP_F_NEW flag. On failure, delete only those entries and clear the deletion mark on the pre-existing ones, so a failed replace leaves the source list untouched. Retain the flag until the whole operation succeeds and then clear it. Also stop vxlan_mdb_remote_src_add() from deleting a pre-existing entry it only looked up when adding that entry's forwarding entry fails.
References
- ubuntu.com/security/CVE-2026-68116 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-68116 (opens in a new tab)
- git.kernel.org/stable/c/54a3c27b357dfb34f327f89bfadeb998bef8051e (opens in a new tab)
- git.kernel.org/stable/c/2c54dff57606590fa4abec46bab6bea3133f1539 (opens in a new tab)
- git.kernel.org/stable/c/dcd9b465965422b9654f6026e8a2fa8984f74c3c (opens in a new tab)
- git.kernel.org/stable/c/79370b573e92e8f190eb5f9a511fa5398340d8b2 (opens in a new tab)
- git.kernel.org/stable/c/5bc8fc1d2ff802eec839e03adef5df597421898d (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8889-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8886-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8888-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8887-3 (opens in a new tab)