Affects widely deployed Linux kernel (core infrastructure); exploit could disrupt IT ops across many sectors.
CVE-2026-31712
Linux ksmbd SMB DACL OOB read can enable kernel compromise
Is CVE-2026-31712 being exploited?
Not confirmed. CVE-2026-31712 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.32% probability of exploitation in the next 30 days.
How severe is CVE-2026-31712?
CVE-2026-31712 is rated High with a CVSS score of 8.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-31712?
Yes. A fix has been recorded for CVE-2026-31712. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-31712 affect?
CVE-2026-31712 affects Linux kernel ksmbd SMB server, Linux distributions with ksmbd enabled. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-31712?
Update to patched kernel and reboot; verify ACL handling.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated SMB client can cause OOB reads in smb_check_perm_dacl, risking kernel state corruption and potential RCE.
Patch when possible
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 282cbbb476b9f35793452bc461934af4c7eca169
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < f20adc4ef7428bc485ee83fd1a592252fb87718b
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 325d4ac11f526cb8964cff14548ccf02d8c756d8
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 95e5aa3c3261da8c95b27d7aecf8ee39b9f86a4c
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 90089584b2e25c4510b7b987387b4405f0673ece
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 151b1799861fde38087c08f613abc2843ef597b0
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < d07b26f39246a82399661936dd0c853983cfade7
- affected5.15
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.