VulnerabilityPublished 25 Jul 2026Updated 6 Nov 2026

CVE-2026-64357: Linux kernel · xfs: fix exchmaps reservation limit check

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in c597c8580d50127fc1221b5a5b653a94d49e23e3 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 17:04 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in c597c8580d50127fc1221b5a5b653a94d49e23e3, a62ef2d13d6e7270dd5e88c6082bf2d0edcd5112, 4707344b0d36d1012c8a1716e20167cd3afdd5f1 +1

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 6 Nov 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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 Linux kernel to c597c8580d50127fc1221b5a5b653a94d49e23e3, a62ef2d13d6e7270dd5e88c6082bf2d0edcd5112, 4707344b0d36d1012c8a1716e20167cd3afdd5f1 or 0a5213bbff62b51c7d4999ac8c7e11ea57d00d45.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 966ceafc7a437105ecfe1cadb3747b2965a260ca, < c597c8580d50127fc1221b5a5b653a94d49e23e3	Fixed in c597c8580d50127fc1221b5a5b653a94d49e23e3
LinuxLinux	Affected ≥ 966ceafc7a437105ecfe1cadb3747b2965a260ca, < a62ef2d13d6e7270dd5e88c6082bf2d0edcd5112	Fixed in a62ef2d13d6e7270dd5e88c6082bf2d0edcd5112
LinuxLinux	Affected ≥ 966ceafc7a437105ecfe1cadb3747b2965a260ca, < 4707344b0d36d1012c8a1716e20167cd3afdd5f1	Fixed in 4707344b0d36d1012c8a1716e20167cd3afdd5f1
LinuxLinux	Affected ≥ 966ceafc7a437105ecfe1cadb3747b2965a260ca, < 0a5213bbff62b51c7d4999ac8c7e11ea57d00d45	Fixed in 0a5213bbff62b51c7d4999ac8c7e11ea57d00d45
LinuxLinux	Affected =6.10	Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: xfs: fix exchmaps reservation limit check xfs_exchmaps_estimate_overhead() adds the bmbt and rmapbt overhead to a local resblks variable, but the final UINT_MAX check still tests req->resblks. That is the reservation value from before the overhead was added. The computed value is stored back in req->resblks and later passed to xfs_trans_alloc(), whose block reservation argument is unsigned int. Check the computed reservation so the existing limit applies to the value that will be used.

References

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