CVE-2026-43377
ksmbd SMB3 key logging may expose credentials in logs.
Is CVE-2026-43377 being exploited?
Not confirmed. CVE-2026-43377 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 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-43377?
CVE-2026-43377 is rated High with a CVSS score of 8.1. 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-2026-43377?
Yes. A fix has been recorded for CVE-2026-43377. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-43377 affect?
CVE-2026-43377 affects Linux kernel ksmbd (SMB server). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-43377?
Update kernel; disable KSMBD_DEBUG_AUTH logging.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Credential leakage: SMB3 signing/encryption keys logged; attackers with log access could steal credentials and impersonate sessions.
Patch when possible
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 4084ed720d7d5f4e975c9e4a6267a552dad3b24a
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < fec5c70b82af3f59f15bb984df94e5ad1fccfb1e
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 3fe2d9ec166b7df9a8df6c0fdcfc210572e27e3f
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 407cc37c21d51f9b9d4d20204b04890880cfa6ae
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < c6b01b997a2094969e315f1ebfc1d64b8ae2163d
- affected>= e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9 and < 441336115df26b966575de56daf7107ed474faed
- 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.