VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98854: Linux kernel · of/overlay: only treat a positive changeset id as registered

Source GCVE Database

Authoritative record:CVE-2026-98854

Not known to be exploited · fixed in cc688475c56d34a2b584141f9544cbe23360080d : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated by Threat Radar · 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 cc688475c56d34a2b584141f9544cbe23360080d, c875407c34dadaef0599834ad9c815f4c9f50d15, c08a54df9d33dcd6ff089adc9434b2c008af3a39 +2

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-x4qh-8j3r-qp8v

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < cc688475c56d34a2b584141f9544cbe23360080d	Fixed in cc688475c56d34a2b584141f9544cbe23360080d
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < c875407c34dadaef0599834ad9c815f4c9f50d15	Fixed in c875407c34dadaef0599834ad9c815f4c9f50d15
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < c08a54df9d33dcd6ff089adc9434b2c008af3a39	Fixed in c08a54df9d33dcd6ff089adc9434b2c008af3a39
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < 44081d708b5b885487bac792db78324b7b4c267d	Fixed in 44081d708b5b885487bac792db78324b7b4c267d
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < 0d1525fdcd3355672b7485d61e55df6824ab5ad1	Fixed in 0d1525fdcd3355672b7485d61e55df6824ab5ad1
LinuxLinux	Affected =4.15	Fixed in–

AI-suggested

A fix has been applied to the Linux kernel source code to address this issue by modifying free_overlay_changeset() to only treat strictly positive IDs as registered. Users should update to the fixed kernel version once available. Patch status is not explicitly confirmed in the provided data; check the vendor advisory or Linux kernel mailing lists for the official patch and update guidance.

Description

A vulnerability in the Linux kernel's of/overlay subsystem was resolved by ensuring that only strictly positive changeset IDs are treated as registered. The issue involved improper handling of negative IDs returned by idr_alloc() on failure, which led to a NULL pointer dereference during cleanup. This could cause a kernel crash due to dereferencing uninitialized memory.

References

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