VulnerabilityPublished 18 Oct 2026

CVE-2026-98868: Linux kernel · dm-pcache: reject a kset that overruns its segment

Source GCVE Database

Authoritative record:CVE-2026-98868· High

Not known to be exploited · fixed in 96e2863b1f81ea61b8d8d5d5a45d3b4c018f8e10 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:05 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 96e2863b1f81ea61b8d8d5d5a45d3b4c018f8e10, 7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb, 01a700e9278da5706c865b9ca3ae70fdb7b4531d

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.

ghsa-94mx-pc7x-6h6x

What to do

Upgrade Linux kernel to 96e2863b1f81ea61b8d8d5d5a45d3b4c018f8e10, 7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb or 01a700e9278da5706c865b9ca3ae70fdb7b4531d.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, < 96e2863b1f81ea61b8d8d5d5a45d3b4c018f8e10	Fixed in 96e2863b1f81ea61b8d8d5d5a45d3b4c018f8e10
LinuxLinux	Affected ≥ 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, < 7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb	Fixed in 7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb
LinuxLinux	Affected ≥ 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0, < 01a700e9278da5706c865b9ca3ae70fdb7b4531d	Fixed in 01a700e9278da5706c865b9ca3ae70fdb7b4531d
LinuxLinux	Affected =6.18	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to reject ksets that overrun their segment cache before processing. Users should update to the fixed kernel version once available.

Description

A vulnerability in the Linux kernel's dm-pcache component was resolved. The flaw involved the handling of a kset whose on-media size could be forged to exceed the remaining segment space, causing a buffer overrun and triggering a kernel BUG_ON condition. The fix involves rejecting any kset whose on-media size exceeds the remaining segment space before processing.

Impact

This vulnerability could cause a kernel crash (BUG_ON) due to out-of-bounds memory access in the dm-pcache segment processing. While no direct exploitation details or privilege escalation are described, such a crash could lead to denial of service on affected systems.

Summary

The Linux kernel dm-pcache module had a vulnerability where the cache_replay(), writeback worker, and GC worker functions read a kset of get_kset_onmedia_size() bytes and advanced the read position by that amount. A maliciously forged key_num could cause the reported size to exceed the segment's remaining space, resulting in the advance operation walking past the segment boundary and triggering a BUG_ON via cache_pos_advance(). The vulnerability is mitigated by rejecting any kset whose on-media size is larger than the remaining segment space before use.

References

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