CVE-2026-64218: Linux kernel · batman-adv: bla: fix report_work leak on backbone_gw purge
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1112.119~20.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.15.0-1112.119~20.04.1, 5.15.0-1117.126~20.04.1, 5.15.0-1117.126~20.04.2 +74
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Jul 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: batman-adv: bla: fix report_work leak on backbone_gw purge batadv_bla_purge_backbone_gw() removes stale backbone gateway entries, but fails to properly handle their associated report_work: - If report_work is running, the purge must wait for it to finish before freeing the backbone_gw, otherwise the worker may access freed memory (e.g. bat_priv). - If report_work is pending, the purge must cancel it and release the reference held for that pending work item. The previous implementation called hlist_for_each_entry_safe() inside a spin_lock_bh() section, but cancel_work_sync() may sleep and therefore cannot be called from within a spinlock-protected region. Restructure the loop to handle one entry per spinlock critical section: acquire the lock, find the next entry to purge, remove it from the hash list, then release the lock before calling cancel_work_sync() and dropping the hash_entry reference. Repeat until no more entries require purging.
References
- ubuntu.com/security/CVE-2026-64218 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-64218 (opens in a new tab)
- git.kernel.org/linus/0459430add32ea41f3e2ef9351610e6d33627a6b (opens in a new tab)
- git.kernel.org/stable/c/0459430add32ea41f3e2ef9351610e6d33627a6b (opens in a new tab)
- git.kernel.org/stable/c/3423a45e5c3d3c5129f88143a9a969787d7d5a0a (opens in a new tab)
- git.kernel.org/stable/c/48663158222b3b7f6ee6791a67d512ede7fc94bb (opens in a new tab)
- git.kernel.org/stable/c/95a7034661274cf5985708bd2f6d86ee46f88fa9 (opens in a new tab)
- git.kernel.org/stable/c/c6de1a5a9c406e30b91f1515a6ce05cc84023baa (opens in a new tab)
- git.kernel.org/stable/c/ce2c0ee4d76d5ee4b391fe0e31334361e25030ec (opens in a new tab)
- git.kernel.org/stable/c/eeddd7bab3d59c1e98642a204141f8c5d6194707 (opens in a new tab)
- git.kernel.org/stable/c/f1303adb1e59582f76c22798a2e2e150e054a9e7 (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8620-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8620-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8620-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8620-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8663-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8664-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8668-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)