CVE-2026-52912: Linux kernel · netfilter: nf_queue: hold bridge skb->dev while queued
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, 16:39 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 4% 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 24 Jun 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: netfilter: nf_queue: hold bridge skb->dev while queued br_pass_frame_up() rewrites skb->dev from the ingress port to the bridge master before queueing bridge LOCAL_IN packets. NFQUEUE only holds references on state.in/out and bridge physdevs, so a queued bridge packet can retain a freed bridge master in skb->dev until reinjection. When the verdict is reinjected later, br_netif_receive_skb() re-enters the receive path with skb->dev still pointing at the freed bridge master, triggering a use-after-free. Store skb->dev in the queue entry, hold a reference on it for the queue lifetime, and use the saved device when dropping queued packets during NETDEV_DOWN handling.
References
- ubuntu.com/security/CVE-2026-52912 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-52912 (opens in a new tab)
- git.kernel.org/linus/e196115ec330a18de415bdb9f5071aa9f08e53ce (opens in a new tab)
- git.kernel.org/stable/c/15d464265120ab9818bd673af301deee09bedab2 (opens in a new tab)
- git.kernel.org/stable/c/19924bdd8a45ebc72a7b84c57fd63057d1dc75ac (opens in a new tab)
- git.kernel.org/stable/c/1e5e20031c5eee8d2e490a90ff4d6a2feecfc3be (opens in a new tab)
- git.kernel.org/stable/c/3823c27099cfe2482299065814adbaa771be9644 (opens in a new tab)
- git.kernel.org/stable/c/3fb0f5c0f64162a8c3f25616a4f1e340b921737f (opens in a new tab)
- git.kernel.org/stable/c/950d809f154dca04e5fbe5d3c8b9c5e44769cd57 (opens in a new tab)
- git.kernel.org/stable/c/a698ac8ab2561cf575d2d9f34095032651dd952e (opens in a new tab)
- git.kernel.org/stable/c/e196115ec330a18de415bdb9f5071aa9f08e53ce (opens in a new tab)
- ubuntu.com/security/notices/USN-8566-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8568-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8569-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-52912 (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-019113.html (opens in a new tab)