VulnerabilityPublished 24 Sep 2026Updated 21 Oct 2026

CVE-2026-93243: Linux kernel · mm/secretmem: properly account locked pages

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in a41c95ac90f285cbe473b9606428b14518896ea4 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 15% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in a41c95ac90f285cbe473b9606428b14518896ea4, 853043cb129473ff2fa0090602be944d96b9d5c9, 97d34aa65c29cca85e3e9050f4c936389b38a054 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 24 Sep 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.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 1507f51255c9ff07d75909a84e7c0d7f3c4b2f49, < a41c95ac90f285cbe473b9606428b14518896ea4	Fixed in a41c95ac90f285cbe473b9606428b14518896ea4
LinuxLinux	Affected ≥ 1507f51255c9ff07d75909a84e7c0d7f3c4b2f49, < 853043cb129473ff2fa0090602be944d96b9d5c9	Fixed in 853043cb129473ff2fa0090602be944d96b9d5c9
LinuxLinux	Affected ≥ 1507f51255c9ff07d75909a84e7c0d7f3c4b2f49, < 97d34aa65c29cca85e3e9050f4c936389b38a054	Fixed in 97d34aa65c29cca85e3e9050f4c936389b38a054
LinuxLinux	Affected ≥ 1507f51255c9ff07d75909a84e7c0d7f3c4b2f49, < 51fba083e454f901947d6a335eeff671171d4714	Fixed in 51fba083e454f901947d6a335eeff671171d4714
LinuxLinux	Affected ≥ 1507f51255c9ff07d75909a84e7c0d7f3c4b2f49, < 3b4f72bdddff69819d665395376329ef21f37a06	Fixed in 3b4f72bdddff69819d665395376329ef21f37a06
LinuxLinux	Affected =5.14	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: mm/secretmem: properly account locked pages secretmem accounts folios by treating memory as if it were mlock()'d and thus limited by the RLIMIT_MEMLOCK limit. However the folios are unevictable and remain so until the inode is evicted, eliminating usual mlock() semantics - mapping folios then unmapping them does not clear their unevictable state, since it depends on AS_UNEVICTABLE, not PG_mlocked. A user can therefore easily work around the RLIMIT_MEMLOCK limit - simply map then unmap and VmLck no longer counts the secretmem range. Worse, folios are not accounted in the process's RSS, meaning the OOM killer won't know to kill the process. Repeatedly mapping/unmapping (or forking) can then result in the consumption of all available system memory with unevictable folios and cause system instability. A secretmem fd can be passed between processes and over fork so a per-process limit simply does not make sense, so follow the precedent set by io_uring, perf, skbuff, iommufd and xdp by tracking the number of locked pages in user_struct->locked_vm. Since the scope tracked is actually inode lifetime, the RLIMIT_MEMLOCK applies per-user not per-process, so it doesn't make sense to bypass for users with CAP_IPC_LOCK, therefore remove this bypass. There is simply no reason to carry on marking the mapping as mlock()'d since it's misleading and the lifecycle is now correctly handled, so remove this too. Note that secretmem does not support any form of truncation (including hole punching) and the folios are unreclaimable, so the folios need only be accounted on fault and unaccounted on inode destruction. __secretmem_account_pages() is more or less a duplicate of the code that io_uring etc. use, but since this is a bug fix that needs backporting, defer any de-duplication efforts to a follow-up. test_mlock_limit() asserts mlock_future_ok() on mmap(), however this has been removed, so remove the test altogether for the fix. A new test will be sent separately for upstream.

References

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