CVE-2026-53189: Linux kernel · mm/huge_memory: update file PMD counter before folio_put()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 7.8 High · fixed in ed5b030931292c94133437ac5e5ff580e498eabd : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 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.
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-16.
- Patch
- Available – fixed in ed5b030931292c94133437ac5e5ff580e498eabd, ae9d4caf6f133e884cf5fcda4982c493b35e5194, 108963978a681c0c468d279cac2b930c27672877 +5
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 |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: mm/huge_memory: update file PMD counter before folio_put() __split_huge_pmd_locked() updates the file/shmem RSS counter after dropping the PMD mapping's folio reference. If folio_put() drops the last reference, mm_counter_file() can later read freed folio state via folio_test_swapbacked(). Move the counter update before folio_put().
References
- git.kernel.org/stable/c/84b3212b166b446faea27ebebb7161405ffceef9 (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/ae9d4caf6f133e884cf5fcda4982c493b35e5194 (opens in a new tab)
- git.kernel.org/stable/c/6c29a8ba084e89499ca77b947e07ae817f9c16ce (opens in a new tab)
- git.kernel.org/stable/c/5f5b604e1e6bde4e889199168ee80fe8306d06ad (opens in a new tab)
- git.kernel.org/stable/c/ed5b030931292c94133437ac5e5ff580e498eabd (opens in a new tab)
- git.kernel.org/stable/c/8d878059924f12c1bc24556a92ec56add74de3c8 (opens in a new tab)