VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98831: Linux kernel · of/overlay: don't leak fragment references when changeset init fails

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in 894573e2fdaeb1b15030b7eebc22615edf28a6cd : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:18 UTC

Severity

Unrated

Rated by Threat Radar · 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 894573e2fdaeb1b15030b7eebc22615edf28a6cd, 702b5db6e7b3865be70675d57d6fd7dde80d02b6, 7a46f1917b320cc8762183b802301da02a191b6a +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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < 894573e2fdaeb1b15030b7eebc22615edf28a6cd	Fixed in 894573e2fdaeb1b15030b7eebc22615edf28a6cd
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < 702b5db6e7b3865be70675d57d6fd7dde80d02b6	Fixed in 702b5db6e7b3865be70675d57d6fd7dde80d02b6
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < 7a46f1917b320cc8762183b802301da02a191b6a	Fixed in 7a46f1917b320cc8762183b802301da02a191b6a
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < 3a23fb158ba517b77a2e5258263bdfdaa480f758	Fixed in 3a23fb158ba517b77a2e5258263bdfdaa480f758
LinuxLinux	Affected ≥ 61b4de4e0b384f4a22c55c3bada604da49cec4e1, < 1d62f0f2bc7edb12ed09f71203df0e47fa4efca4	Fixed in 1d62f0f2bc7edb12ed09f71203df0e47fa4efca4
LinuxLinux	Affected =4.15	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: of/overlay: don't leak fragment references when changeset init fails init_overlay_changeset() stores the number of initialized fragments in ovcs->count only on full success. When find_target() or the __symbols__ lookup fails partway through, the target and overlay references taken for the fragments initialized so far are never dropped: free_overlay_changeset() bounds its cleanup loop by ovcs->count, which is still 0. Store the running count on the error path so free_overlay_changeset() puts whatever was set up. The store is guarded by ovcs->fragments because on the allocation-failure path cnt still holds the counting pass total while there is no fragments array; everywhere else cnt only counts fully-initialized fragments.

References

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