- 5.5MediumCVSS base score
- 0.16%Exploitation in 30 daysEPSS · top 95% 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: ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers smb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn into a local with neither READ_ONCE() nor a NULL check. Both run from oplock_break() after opinfo_get_list() has dropped ci->m_lock, so a concurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL under ci->m_lock within that window. ksmbd_conn_r_count_inc(conn) then writes through NULL at offset 0xc4 -- a remotely triggerable oops. Guard both reads the way compare_guid_key() already does: read opinfo->conn with READ_ONCE() and return early if it is NULL, before allocating the work struct so nothing leaks. A NULL conn means the client is gone and the break is moot, so return 0; oplock_break() treats that as success and runs the normal teardown.
Timeline
ID reserved
By Linux
- 16 days later
· 16 days later
Published
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
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.16% · top 95% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Affected products
- affected 8df4bcdb0a4232192b2445256c39b787d58ef14d – < 945a86b21b40fb17183f5b27461baa6f03e2467f
- affected c8efcc786146a951091588e5fa7e3c754850cb3c – < 1ff58dcfcab434ebb51649da33774fbb8e1f7b67
- affected c8efcc786146a951091588e5fa7e3c754850cb3c – < e735dbd489e3ea02be78dba991056fe1138be51e
- affected c8efcc786146a951091588e5fa7e3c754850cb3c – < 75e33deda658c1ab3a9336cbdb1436536f9b3660
- affected c8efcc786146a951091588e5fa7e3c754850cb3c – < b003086d76968298f22e7cf62239833b5a3a06b1
- affected 6.6.32 – < 6.6.143
- affected 6.9
- unaffected < 6.9
- unaffected 6.6.143 – ≤ 6.6.*
- unaffected 6.12.94 – ≤ 6.12.*
- unaffected 6.18.36 – ≤ 6.18.*
- unaffected 7.0.13 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References5
- https://git.kernel.org/stable/c/945a86b21b40fb17183f5b27461baa6f03e2467f (opens in a new tab)
- https://git.kernel.org/stable/c/1ff58dcfcab434ebb51649da33774fbb8e1f7b67 (opens in a new tab)
- https://git.kernel.org/stable/c/e735dbd489e3ea02be78dba991056fe1138be51e (opens in a new tab)
- https://git.kernel.org/stable/c/75e33deda658c1ab3a9336cbdb1436536f9b3660 (opens in a new tab)
- https://git.kernel.org/stable/c/b003086d76968298f22e7cf62239833b5a3a06b1 (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-2026-39222 (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-2026-53271)Record last updated .