VulnerabilityPublished 6 Oct 2026Updated 19 Oct 2026

CVE-2026-98223: Linux kernel · mm: filemap: retain mapped dropbehind folios

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 2897601dffe576fcd87a4259102f41f7fb0cbfc8 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2897601dffe576fcd87a4259102f41f7fb0cbfc8, 848d2ce2fce15fbdc083fbf9691bfa72911033c4, 77c0fade37c80e8aa16ac048a9828249055e3f66

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 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 Linux kernel to 2897601dffe576fcd87a4259102f41f7fb0cbfc8, 848d2ce2fce15fbdc083fbf9691bfa72911033c4 or 77c0fade37c80e8aa16ac048a9828249055e3f66.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ fb7d3bc4149395c1ae99029c852eab6c28fc3c88, < 2897601dffe576fcd87a4259102f41f7fb0cbfc8	Fixed in 2897601dffe576fcd87a4259102f41f7fb0cbfc8
LinuxLinux	Affected ≥ fb7d3bc4149395c1ae99029c852eab6c28fc3c88, < 848d2ce2fce15fbdc083fbf9691bfa72911033c4	Fixed in 848d2ce2fce15fbdc083fbf9691bfa72911033c4
LinuxLinux	Affected ≥ fb7d3bc4149395c1ae99029c852eab6c28fc3c88, < 77c0fade37c80e8aa16ac048a9828249055e3f66	Fixed in 77c0fade37c80e8aa16ac048a9828249055e3f66
LinuxLinux	Affected =6.14	Fixed in–

AI-suggested

A fix for this vulnerability is available and has been applied in the Linux kernel. Users and administrators should update to the fixed kernel versions identified by the commits 2897601dffe576fcd87a4259102f41f7fb0cbfc8, 848d2ce2fce15fbdc083fbf9691bfa72911033c4, and 77c0fade37c80e8aa16ac048a9828249055e3f66. No additional mitigation is required beyond applying the official patch.

Description

A vulnerability in the Linux kernel's memory management subsystem related to the handling of mapped dropbehind folios has been resolved. The issue involves improper retention of mapped dropbehind folios, which can lead to a sleeping-in-atomic warning due to inappropriate locking and sleeping behavior in non-preemptible task contexts. The fix ensures that mapped folios are retained correctly to avoid unsafe unmapping operations during writeback completion.

Impact

The vulnerability can cause kernel warnings related to sleeping in atomic context, which may lead to system instability or crashes under certain conditions. This is primarily a stability and reliability issue rather than a direct security compromise such as privilege escalation or information disclosure. No known exploits in the wild have been reported.

Summary

CVE-2026-98223 addresses a flaw in the Linux kernel's filemap component where fault-around operations could map ready dropbehind folios without clearing the dropbehind state via the normal page-cache lookup. Since a mapping represents a competing cached user, the folio should be retained rather than forcibly unmapped when writeback completes. The vulnerability arises because folio_unmap_invalidate() can call unmap_mapping_folio(), which takes the i_mmap_rwsem semaphore and may sleep, causing a sleeping-in-atomic warning when folio_end_dropbehind() runs in a non-preemptible task context. The patch retains mapped folios to avoid this unsafe path, while unmapped dropbehind folios continue through the existing invalidation path.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 12:10 UTC

Technical details

References

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