VulnerabilityPublished 16 Sep 2026Updated 21 Oct 2026

CVE-2026-89962: Linux kernel · powerpc/kexec_file: Prevent kexec range truncation

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in ffbdc2a3834a3e47bac7236a71bbc82b45c83832 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:07 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 ffbdc2a3834a3e47bac7236a71bbc82b45c83832, fa40f9dbdd4af53e7445d9135b5b207eb8adf372, da88a2a2119e4fd0e8919a7a2448682f574e1545 +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 ≥ 180adfc532a83c1d74146449f7385f767d4b8059, < ffbdc2a3834a3e47bac7236a71bbc82b45c83832	Fixed in ffbdc2a3834a3e47bac7236a71bbc82b45c83832
LinuxLinux	Affected ≥ 180adfc532a83c1d74146449f7385f767d4b8059, < fa40f9dbdd4af53e7445d9135b5b207eb8adf372	Fixed in fa40f9dbdd4af53e7445d9135b5b207eb8adf372
LinuxLinux	Affected ≥ 180adfc532a83c1d74146449f7385f767d4b8059, < da88a2a2119e4fd0e8919a7a2448682f574e1545	Fixed in da88a2a2119e4fd0e8919a7a2448682f574e1545
LinuxLinux	Affected ≥ 180adfc532a83c1d74146449f7385f767d4b8059, < c4cb547f26d9b73b489c5278d0c8db837c5a174f	Fixed in c4cb547f26d9b73b489c5278d0c8db837c5a174f
LinuxLinux	Affected ≥ 180adfc532a83c1d74146449f7385f767d4b8059, < 9ef63622e6cee588ea4b763a6afc87065254b36a	Fixed in 9ef63622e6cee588ea4b763a6afc87065254b36a
LinuxLinux	Affected =5.9	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: powerpc/kexec_file: Prevent kexec range truncation Sashiko AI review pointed out the following issue. The __merge_memory_ranges() function incorrectly handles overlapping memory ranges when merging them. Although sort_memory_ranges() sorts all ranges by their start address in ascending order beforehand, the merge logic remains defective in two ways: 1. It compares the current range's start against the previous element (i-1) instead of the running target index (idx) 2. It unconditionally overwrites 'ranges[idx].end' with 'ranges[i].end'. This logic flaw leads to critical memory truncation when a larger memory range completely subsumes subsequent smaller ranges. For example, consider a sorted input array with three ranges: Range A (idx=0): [0x1000 - 0x9000] Range B (i=1): [0x2000 - 0x5000] (completely inside Range A) Range C (i=2): [0x6000 - 0x8000] (completely inside Range A) 1. When i=1 (Range B): ranges[1].start (0x2000) <= ranges[0].end + 1 (0x9001) is TRUE. The code executes: ranges[0].end = ranges[1].end, which erroneously shrinks Range A's end from 0x9000 down to 0x5000. 2. When i=2 (Range C): ranges[2].start (0x6000) <= ranges[1].end + 1 (0x5001) is FALSE. The code falls into the else block, creating a broken new range. As a result, valid memory fragments [0x5001 - 0x5fff] and [0x8001 - 0x9000] are completely lost from the kexec exclude lists, potentially allowing the crash kernel to overwrite active memory, causing data corruption or crashes. Fix this by ensuring the start of the current range is compared against the end of the active merged range (idx), and use max() to safely prevent the outer boundary from being truncated.

References

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