{"cve":"CVE-2026-97564","nvd":{"published":"2026-09-25T11:17:07.007","modified":"2026-10-19T10:17:25.503","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: reject userspace cifs.idmap descriptions\n\ncifs.idmap key descriptions carry authority-bearing fields (owner and\ngroup SIDs and uid/gid values in \"os:\"/\"gs:\"/\"oi:\"/\"gi:\" form) that the\ncifs.idmap upcall helper treats as kernel-originating inputs.  Unlike\nits sibling cifs.spnego, the cifs.idmap key type has no vet_description\nhook, so userspace can create keys of this type through\nrequest_key(2)/add_key(2) and supply those fields without CIFS origin.\nA request_key(2) call with a non-NULL callout then drives a root\nusermodehelper upcall (/sbin/request-key -> cifs.idmap) that consumes\nthe unvetted description in root context.\n\nOnly accept cifs.idmap descriptions while CIFS is using its private\nroot_cred to request the key.  id_to_sid()/sid_to_id() already run\nunder override_creds(root_cred), so the kernel-originated path is\nunaffected.\n\nThis mirrors commit 3da1fdf4efbc (\"smb: client: reject userspace\ncifs.spnego descriptions\"), which applied the same restriction to\ncifs.spnego.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/17c93bcd17755523c21abb22cbf2a41a6eb0caaf","https://git.kernel.org/stable/c/1d3b24b16a0b013792e8f1e3ed060f0b46f537d1","https://git.kernel.org/stable/c/96751028c0d4dec785709ea3eb0ab38a4f2ded96","https://git.kernel.org/stable/c/d9d7eeb0cea5b55b82888f443622fd8d4ee064f3","https://git.kernel.org/stable/c/e5964064e3fbe6325893408faff08ca33de0e2c3"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:02.509636177+00:00"},"epss":{"cve":"CVE-2026-97564","score":0.00211,"percentile":0.11304,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}