CVE-2026-97564smb: client: reject userspace cifs.idmap descriptions
- —Not scoredno CVSS score yet
- 0.22%Exploitation in 30 daysEPSS · top 88% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: smb: client: reject userspace cifs.idmap descriptions cifs.idmap key descriptions carry authority-bearing fields (owner and group SIDs and uid/gid values in "os:"/"gs:"/"oi:"/"gi:" form) that the cifs.idmap upcall helper treats as kernel-originating inputs. Unlike its sibling cifs.spnego, the cifs.idmap key type has no vet_description hook, so userspace can create keys of this type through request_key(2)/add_key(2) and supply those fields without CIFS origin. A request_key(2) call with a non-NULL callout then drives a root usermodehelper upcall (/sbin/request-key -> cifs.idmap) that consumes the unvetted description in root context. Only accept cifs.idmap descriptions while CIFS is using its private root_cred to request the key. id_to_sid()/sid_to_id() already run under override_creds(root_cred), so the kernel-originated path is unaffected. This mirrors commit 3da1fdf4efbc ("smb: client: reject userspace cifs.spnego descriptions"), which applied the same restriction to cifs.spnego.
Timeline
ID reserved
By Linux
- 1 day later
· 1 day later
Published
- 35 days later
· 35 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
No CVSS score yet: neither the CNA, CISA nor NVD has scored this CVE. NVD status: Received.
- EPSS (exploitation in 30 days)
- 0.22% · top 88% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 4d79dba0e00749fa40de8ef13a9b85ce57a1603b – < 91da70a2e5c6f54e1316d51e0e6911e78ef5e09a
- affected 4d79dba0e00749fa40de8ef13a9b85ce57a1603b – < 856cb3f05b49d23dc1542f78696e20c4ea6dd7de
- affected 4d79dba0e00749fa40de8ef13a9b85ce57a1603b – < f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a
- affected 4d79dba0e00749fa40de8ef13a9b85ce57a1603b – < 17c93bcd17755523c21abb22cbf2a41a6eb0caaf
- affected 4d79dba0e00749fa40de8ef13a9b85ce57a1603b – < e5964064e3fbe6325893408faff08ca33de0e2c3
- affected 4d79dba0e00749fa40de8ef13a9b85ce57a1603b – < 96751028c0d4dec785709ea3eb0ab38a4f2ded96
- affected 4d79dba0e00749fa40de8ef13a9b85ce57a1603b – < 1d3b24b16a0b013792e8f1e3ed060f0b46f537d1
- affected 4d79dba0e00749fa40de8ef13a9b85ce57a1603b – < d9d7eeb0cea5b55b82888f443622fd8d4ee064f3
- affected 3.0
- unaffected < 3.0
- unaffected 5.10.273 – ≤ 5.10.*
- unaffected 5.15.224 – ≤ 5.15.*
- unaffected 6.1.189 – ≤ 6.1.*
- unaffected 6.6.158 – ≤ 6.6.*
- unaffected 6.12.111 – ≤ 6.12.*
- unaffected 6.18.53 – ≤ 6.18.*
- unaffected 7.2.7 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/91da70a2e5c6f54e1316d51e0e6911e78ef5e09a (opens in a new tab)
- https://git.kernel.org/stable/c/856cb3f05b49d23dc1542f78696e20c4ea6dd7de (opens in a new tab)
- https://git.kernel.org/stable/c/f29c1ec0e7d8c887a91df3f93bb4617c0ac95c6a (opens in a new tab)
- https://git.kernel.org/stable/c/17c93bcd17755523c21abb22cbf2a41a6eb0caaf (opens in a new tab)
- https://git.kernel.org/stable/c/e5964064e3fbe6325893408faff08ca33de0e2c3 (opens in a new tab)
- https://git.kernel.org/stable/c/96751028c0d4dec785709ea3eb0ab38a4f2ded96 (opens in a new tab)
- https://git.kernel.org/stable/c/1d3b24b16a0b013792e8f1e3ed060f0b46f537d1 (opens in a new tab)
- https://git.kernel.org/stable/c/d9d7eeb0cea5b55b82888f443622fd8d4ee064f3 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-86872 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-97564)Record last updated .