CVE-2026-97554smb: client: avoid using uninitialized SIDs in cifs_posix_to_fattr()
- —Not scoredno CVSS score yet
- 0.21%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: avoid using uninitialized SIDs in cifs_posix_to_fattr() cifs_posix_to_fattr() ignores the return value of posix_info_parse(). When a malformed POSIX directory entry is encountered (e.g. invalid SID lengths from an untrusted server), posix_info_parse() returns -1 without populating the 'parsed' struct. The uninitialized stack memory in parsed.owner and parsed.group is then passed to sid_to_id(), which processes the garbage bytes and passes them to request_key() to construct a SID string, potentially leaking kernel stack contents to the userspace idmap daemon. Fix this by checking the return value and skipping the SID-to-id mapping when parsing fails. The remaining fattr fields (timestamps, mode, etc.) are populated directly from the 'info' pointer so they are unaffected.
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)
- 0.21% · top 88% of all CVEs (15 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Not scored.
Affected products
- affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 – < 1915b69e36906968e2b698699d0f219875ae846e
- affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 – < 604feb3e8141bf11f5afd48d36d401fee5af9536
- affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 – < 33106019c3be57b5fc6411cfaad6d98214a51265
- affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 – < 2be31f252ade791b84f7164991f14436aed1d4b9
- affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 – < c9a8b60ce140a68d172452f418137fc7ddbae7db
- affected 9934430e2178d5164eb1ac91a9b092f9e7e64745 – < da6e25842431982d5a53cf00d925b98c690f4467
- affected dd80b98bdf0a4b3206739f3513b0518f27a7b4ef
- affected d8e39c11f66125f49de55537a6efc8ecadf4a0f7
- affected 5.8.17 – < 5.9
- affected 5.9.2 – < 5.10
- affected 5.10
- unaffected < 5.10
- unaffected 6.1.191 – ≤ 6.1.*
- unaffected 6.6.160 – ≤ 6.6.*
- unaffected 6.12.114 – ≤ 6.12.*
- unaffected 6.18.57 – ≤ 6.18.*
- unaffected 7.2.7 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References6
- https://git.kernel.org/stable/c/1915b69e36906968e2b698699d0f219875ae846e (opens in a new tab)
- https://git.kernel.org/stable/c/604feb3e8141bf11f5afd48d36d401fee5af9536 (opens in a new tab)
- https://git.kernel.org/stable/c/33106019c3be57b5fc6411cfaad6d98214a51265 (opens in a new tab)
- https://git.kernel.org/stable/c/2be31f252ade791b84f7164991f14436aed1d4b9 (opens in a new tab)
- https://git.kernel.org/stable/c/c9a8b60ce140a68d172452f418137fc7ddbae7db (opens in a new tab)
- https://git.kernel.org/stable/c/da6e25842431982d5a53cf00d925b98c690f4467 (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-2026-86862 (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)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-97554)Record last updated .