VulnerabilityPublished 16 Sep 2026Updated 21 Oct 2026

CVE-2026-89834: Linux kernel · f2fs: fix to migrate all curseg types during free_segment_range

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in d358d2fc6be11eefde5eb1286f1c43a6d0330db6 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Unrated

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.
Patch: Available – fixed in d358d2fc6be11eefde5eb1286f1c43a6d0330db6, b9776094aa7118e8e5dfdcd791ffc8330c5ca408, b8ae1228c153622afa71a179c9d4dc268117e0f0 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 16 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

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ d0b9e42ab6155dc05fc83f00af9f45d4dd02264d, < d358d2fc6be11eefde5eb1286f1c43a6d0330db6	Fixed in d358d2fc6be11eefde5eb1286f1c43a6d0330db6
LinuxLinux	Affected ≥ d0b9e42ab6155dc05fc83f00af9f45d4dd02264d, < b9776094aa7118e8e5dfdcd791ffc8330c5ca408	Fixed in b9776094aa7118e8e5dfdcd791ffc8330c5ca408
LinuxLinux	Affected ≥ d0b9e42ab6155dc05fc83f00af9f45d4dd02264d, < b8ae1228c153622afa71a179c9d4dc268117e0f0	Fixed in b8ae1228c153622afa71a179c9d4dc268117e0f0
LinuxLinux	Affected ≥ d0b9e42ab6155dc05fc83f00af9f45d4dd02264d, < 8ec06f50ddd8d201bd7e55b896ae28ed9d4cb7d1	Fixed in 8ec06f50ddd8d201bd7e55b896ae28ed9d4cb7d1
LinuxLinux	Affected ≥ d0b9e42ab6155dc05fc83f00af9f45d4dd02264d, < 3b85edf3391f3e1f624f409a7d2d239885f567b7	Fixed in 3b85edf3391f3e1f624f409a7d2d239885f567b7
LinuxLinux	Affected =5.10	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to migrate all curseg types during free_segment_range In free_segment_range(), the curseg evacuation loop only iterates up to NR_CURSEG_PERSIST_TYPE (0..5), missing non-persistent in-memory curseg types such as CURSEG_COLD_DATA_PINNED and CURSEG_ALL_DATA_ATGC. Even though these in-memory curseg types are not saved in the on-disk checkpoint header, they still occupy active physical segments at runtime. If an active in-memory curseg happens to be allocated within the segment range being truncated during filesystem shrink, failing to evacuate it will cause subsequent writes to the curseg attempting out-of-bounds I/O on the truncated storage range. Fix this by expanding the curseg evacuation loop upper bound to NR_CURSEG_TYPE to ensure all active curseg types are safely migrated out of the target range.

References

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