VulnerabilityPublished 17 Sep 2026Updated 5 Oct 2026

CVE-2026-93198: Linux kernel · dm-pcache: validate the persisted dirty_tail chain at load

Affects Linux kernelSource GCVE Database

Authoritative record:CVE-2026-93198

Not known to be exploited.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 10% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation evidence

Disclosed: evidence found.
CVE published 17 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

Affected software

Product	Affected	Fixed in
Ubuntu 26.04 LTSlinux`pkg:deb/ubuntu/linux?arch=source&distro=resolute`Other threats	Affected 6.17.0-5.5 – 7.0.0-38.38 23 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=resolute`Other threats	Affected 6.17.0-1003.3 – 7.0.0-1017.17 15 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resolute`Other threats	Affected 7.0.0-1003.3 – 7.0.0-1016.16 9 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=resolute`Other threats	Affected 6.17.0-1002.2 – 7.0.0-1014.14 13 affected builds	Fixed in–
Ubuntu 26.04 LTSlinux-gke`pkg:deb/ubuntu/linux-gke?arch=source&distro=resolute`Other threats	Affected 7.0.0-1002.3 – 7.0.0-1008.9 6 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The vulnerability has been resolved in the affected linux-hwe-edge kernel versions by adding validation of the persisted dirty_tail chain at load time. Users should apply the official kernel updates that include this fix. Patch status is not explicitly stated in the input data, so check the vendor advisory for current remediation guidance.

Description

A vulnerability in the Linux kernel's dm-pcache component involves improper validation of the persisted dirty_tail chain at load time. The flaw allows a crafted cache image to cause the writeback worker to re-arm itself indefinitely without delay, potentially leading to resource exhaustion or denial of service. This issue affects specific versions of the linux-hwe-edge kernel. The vulnerability has been resolved by validating the dirty_tail chain during table load and failing the load if the chain does not terminate within a set number of hops.

Impact

An attacker able to supply a crafted cache image could cause the writeback worker to enter an infinite loop of re-arming with no delay, potentially leading to resource exhaustion or denial of service conditions on the affected system. There is no indication of code execution or data corruption beyond this denial of service impact.

Summary

The Linux kernel's dm-pcache module had a vulnerability where the writeback worker follows the persisted dirty_tail chain decoded from the cache device independently of the key_tail chain. Since the on-media fields are authenticated only by a crc32c with a fixed seed, a crafted image can cause the dirty_tail chain to never terminate, causing cache_writeback_fn() to re-arm itself with no delay indefinitely. The fix involves walking the dirty_tail chain once at load with the same hop cap used by cache_replay() and failing the table load with an I/O error (-EIO) if the chain does not reach an end within the allowed number of segments.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 24 Oct 2026, 23:59 UTC

Technical details

References

Community reviews

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