CVE-2026-53189: Linux kernel · mm/huge_memory: update file PMD counter before folio_put()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1117.124~20.04.1 : 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 5.15.0-1117.124~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1122.131~20.04.1 +45
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 25 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 should be applied. Fixed versions include 5.15.0-1111.115~20.04.1 and later releases as listed in the established facts. Users 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 huge memory management subsystem was resolved by updating the file PMD counter before calling folio_put(). The flaw involved a race condition where the file/shmem RSS counter was updated after dropping the PMD mapping's folio reference, potentially allowing reading of freed folio state. This issue affects specific Linux kernel versions and has been fixed in later releases. The vulnerability has a CVSS score of 7.8, indicating high impact on confidentiality, integrity, and availability. No known exploits are reported in the wild. Official patches are available and should be applied.
References
- ubuntu.com/security/CVE-2026-53189 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-53189 (opens in a new tab)
- git.kernel.org/linus/8d878059924f12c1bc24556a92ec56add74de3c8 (opens in a new tab)
- git.kernel.org/stable/c/108963978a681c0c468d279cac2b930c27672877 (opens in a new tab)
- git.kernel.org/stable/c/459771c9cf30f378bdbd30fc65d17f7eb931bb59 (opens in a new tab)
- git.kernel.org/stable/c/5f5b604e1e6bde4e889199168ee80fe8306d06ad (opens in a new tab)
- git.kernel.org/stable/c/6c29a8ba084e89499ca77b947e07ae817f9c16ce (opens in a new tab)
- git.kernel.org/stable/c/84b3212b166b446faea27ebebb7161405ffceef9 (opens in a new tab)
- git.kernel.org/stable/c/8d878059924f12c1bc24556a92ec56add74de3c8 (opens in a new tab)
- git.kernel.org/stable/c/ae9d4caf6f133e884cf5fcda4982c493b35e5194 (opens in a new tab)
- git.kernel.org/stable/c/ed5b030931292c94133437ac5e5ff580e498eabd (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8727-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8726-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-8800-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8760-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8728-2 (opens in a new tab)