Widely-used Linux kernel ksmbd SMB server; UAF risk could enable memory corruption and privilege escalation.
CVE-2026-43379
Kernel ksmbd use-after-free in smb_lazy_parent_lease_break_close (race).
Is CVE-2026-43379 being exploited?
Not confirmed. CVE-2026-43379 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 0.44% probability of exploitation in the next 30 days.
How severe is CVE-2026-43379?
CVE-2026-43379 is rated Critical with a CVSS score of 9.8. 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-2026-43379?
Yes. A fix has been recorded for CVE-2026-43379. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-43379 affect?
CVE-2026-43379 affects Linux kernel ksmbd. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43379?
Patch kernel immediately to patched version
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Kernel use-after-free via ksmbd SMB server race; potential memory corruption and local privilege escalation.
Immediate action required
- affected>= 27b40b7bfcd121fe13a150ffe11957630cf49246 and < bf4d66d72e4a9e268c1012c331ce9eaedb5e2086
- affected>= 5fb282ba4fef8985a5acf2b32681f2ec07732561 and < 960699317d39f46611f4ebeb69edc567c1f4e6b6
- affected>= 5fb282ba4fef8985a5acf2b32681f2ec07732561 and < dbbd328cf58261ca239756fe1c0d10c9518d3399
- affected>= 5fb282ba4fef8985a5acf2b32681f2ec07732561 and < b3568347c51c46e2cabc356bc34676df98296619
- affected>= 5fb282ba4fef8985a5acf2b32681f2ec07732561 and < eac3361e3d5dd8067b3258c69615888eb45e9f25
- affected>= 6.6.32 and < 6.6.130
- affected6.9
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.