CVE-2026-53000: Linux kernel · netfilter: nat: use kfree_rcu to release ops
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 7.0.0-28.28~24.04.1 : patch Linux kernel soon.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 7.0.0-28.28~24.04.1, 7.0.0-1016.16~24.04.1, 6.8.0-1035.38 +12
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.
AI-suggested
A patch is available and has been released in Linux kernel versions 7.0.0-28.28 and later, as well as other related fixed versions. Users and administrators should update affected Linux kernel versions to these fixed releases to remediate the vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Description
A vulnerability in the Linux kernel's netfilter NAT subsystem was resolved by updating the release mechanism for nf_hook_ops structures to use kfree_rcu. This issue arose due to changes introduced in kernel version 5.14 that allowed userspace to dump active netfilter hooks, exposing previously hidden nat hooks. The flaw could lead to use-after-free conditions affecting kernel memory management. Multiple Linux kernel versions prior to 7.0.0-28.28 and specific earlier builds are affected. The vulnerability has a CVSS score of 7.8, indicating a medium severity with high impact on confidentiality, integrity, and availability. A patch is available and included in fixed kernel versions starting from 7.0.0-28.28 and related releases. No known exploits in the wild have been reported.
References
- ubuntu.com/security/CVE-2026-53000 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-53000 (opens in a new tab)
- git.kernel.org/linus/6eda0d771f94267f73f57c94630aa47e90957915 (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)
- nvd.nist.gov/vuln/detail/CVE-2026-53000 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:55445 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-53000 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2492273 (opens in a new tab)
- git.kernel.org/stable/c/32fdd2e38e7435a368d88f5977a7d6585ebc8b0e (opens in a new tab)
- git.kernel.org/stable/c/3c7511f38ab511b791196b13ae48bf4973bf7dfd (opens in a new tab)
- git.kernel.org/stable/c/6eda0d771f94267f73f57c94630aa47e90957915 (opens in a new tab)
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-53000.json (opens in a new tab)
- ubuntu.com/security/notices/USN-8593-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8603-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8618-1 (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-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8781-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-3 (opens in a new tab)