VulnerabilityPublished 18 Oct 2026

CVE-2026-98844: Linux kernel · netfs: clear post-EOF pagecache when extending a file via write

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in f8f7d86b3537e885ee620898a38b749fba8a8456 : 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 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in f8f7d86b3537e885ee620898a38b749fba8a8456, a7036a73671fc83d299bc770710fe996d9fef9ca, 98f6a4589e0f5f6cf819b8dd45605efc481c06ce +1

Exploitation evidence

Disclosed: evidence found.
CVE published 18 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 f8f7d86b3537e885ee620898a38b749fba8a8456, a7036a73671fc83d299bc770710fe996d9fef9ca, 98f6a4589e0f5f6cf819b8dd45605efc481c06ce or 69bf14300b50631e7c2271289d347bbd1b19a06c.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 153a9961b551101cd38e94e26cd92fbfd198b19b, < f8f7d86b3537e885ee620898a38b749fba8a8456	Fixed in f8f7d86b3537e885ee620898a38b749fba8a8456
LinuxLinux	Affected ≥ 153a9961b551101cd38e94e26cd92fbfd198b19b, < a7036a73671fc83d299bc770710fe996d9fef9ca	Fixed in a7036a73671fc83d299bc770710fe996d9fef9ca
LinuxLinux	Affected ≥ 153a9961b551101cd38e94e26cd92fbfd198b19b, < 98f6a4589e0f5f6cf819b8dd45605efc481c06ce	Fixed in 98f6a4589e0f5f6cf819b8dd45605efc481c06ce
LinuxLinux	Affected ≥ 153a9961b551101cd38e94e26cd92fbfd198b19b, < 69bf14300b50631e7c2271289d347bbd1b19a06c	Fixed in 69bf14300b50631e7c2271289d347bbd1b19a06c
LinuxLinux	Affected =6.8	Fixed in–
Red Hatredhat/kernel`pkg:rpm/redhat/kernel`Other threats	Affected =6.8	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 fix is available and has been applied in Linux kernel version 6.8 and later. Users and administrators should update to version 6.8 or later to remediate this issue. No additional mitigation actions are required beyond applying the official fix.

Description

CVE-2026-98844 is a vulnerability in the Linux kernel's netfs subsystem where stale pagecache data beyond the end-of-file (EOF) is not cleared when extending a file via write. This can lead to exposure of stale data left by previous memory-mapped writes. The issue is fixed by zeroing the tail of the pagecache folio straddling the EOF before an extending write, ensuring no stale data is exposed. The fix also handles concurrent writes and respects non-blocking IO flags.

Impact

The vulnerability could allow exposure of stale data beyond the EOF in files extended via write operations, potentially leaking sensitive information previously written through memory-mapped IO. This stale data exposure occurs because the pagecache is not properly cleared before extending writes. The fix prevents this by zeroing the relevant pagecache area. There is no indication of active exploitation in the wild.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 09:42 UTC

Technical details

References

Community reviews

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