VulnerabilityPublished 25 Sep 2026Updated 30 Oct 2026

CVE-2026-97564: Linux kernel · smb: client: reject userspace cifs.idmap descriptions

Source GCVE Database

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Authoritative record:CVE-2026-97564· High

Not known to be exploited · fixed in f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a : patch Linux kernel soon.

Data as of 30 Oct 2026, 17:33 UTC

Severity

High

Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a, e5964064e3fbe6325893408faff08ca33de0e2c3, d9d7eeb0cea5b55b82888f443622fd8d4ee064f3 +5

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Sep 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 30 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.
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.

ghsa-3fc8-28wq-wq67

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 4d79dba0e00749fa40de8ef13a9b85ce57a1603b, < f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a	Fixed in f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a
LinuxLinux	Affected ≥ 4d79dba0e00749fa40de8ef13a9b85ce57a1603b, < e5964064e3fbe6325893408faff08ca33de0e2c3	Fixed in e5964064e3fbe6325893408faff08ca33de0e2c3
LinuxLinux	Affected ≥ 4d79dba0e00749fa40de8ef13a9b85ce57a1603b, < d9d7eeb0cea5b55b82888f443622fd8d4ee064f3	Fixed in d9d7eeb0cea5b55b82888f443622fd8d4ee064f3
LinuxLinux	Affected ≥ 4d79dba0e00749fa40de8ef13a9b85ce57a1603b, < 96751028c0d4dec785709ea3eb0ab38a4f2ded96	Fixed in 96751028c0d4dec785709ea3eb0ab38a4f2ded96
LinuxLinux	Affected ≥ 4d79dba0e00749fa40de8ef13a9b85ce57a1603b, < 856cb3f05b49d23dc1542f78696e20c4ea6dd7de	Fixed in 856cb3f05b49d23dc1542f78696e20c4ea6dd7de
LinuxLinux	Affected ≥ 4d79dba0e00749fa40de8ef13a9b85ce57a1603b, < 91da70a2e5c6f54e1316d51e0e6911e78ef5e09a	Fixed in 91da70a2e5c6f54e1316d51e0e6911e78ef5e09a

AI-suggested

Apply the official kernel patch that restricts acceptance of cifs.idmap descriptions to those requested with the kernel's private root credentials. This fix ensures that only kernel-originated inputs are accepted, mitigating the vulnerability.

Description

A vulnerability in the Linux kernel's SMB client allows userspace to create cifs.idmap keys with authority-bearing fields that the kernel mistakenly treats as originating from the kernel. This can lead to unvetted descriptions being consumed in root context. The issue has been resolved by restricting acceptance of cifs.idmap descriptions to only those requested using the kernel's private root credentials.

References

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