Kernel SMB (ksmbd) vuln affects Linux servers broadly; unauthenticated remote memory disclosure and crashes risk make it high-impact for enterprise infrastructure.
CVE-2026-68431
Linux kernel ksmbd: malformed SMB2 transform allows remote kernel memory disclosure
Is CVE-2026-68431 being exploited?
Not confirmed. CVE-2026-68431 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 0.37% probability of exploitation in the next 30 days.
How severe is CVE-2026-68431?
CVE-2026-68431 is rated Critical with a CVSS score of 9.1. 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-2026-68431?
Yes. A fix has been recorded for CVE-2026-68431. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-68431 affect?
CVE-2026-68431 affects Linux kernel (ksmbd), Servers exposing SMB (TCP/445), SMB2/SMB3 connections on affected kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-68431?
Apply vendor kernel updates ASAP; block SMB (TCP/445) from untrusted networks
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Unauthenticated remote attacker can send malformed SMB2 transform packets to read kernel memory and cause crashes on affected hosts.
Immediate action required
- affected>= df3a4518aee64f21bcafa891105b468413f27431 and < 22f1aa35b87e471cc31b35b74451f46630863b12
- affected>= 543c12c2644e772caa6880662c2a852cfdc5a10c and < 928dda88d0e13fbca381255028f65b244343a4ea
- affected>= 368ba06881c395f1c9a7ba22203cf8d78b4addc0 and < d8e5c5672724b8f3c4c099d2cf60239c996e5424
- affected>= 368ba06881c395f1c9a7ba22203cf8d78b4addc0 and < 32e486b70c256d5ef4baa5a2936ade2fea50e8eb
- affected>= 368ba06881c395f1c9a7ba22203cf8d78b4addc0 and < d9e9753dfd43bd27c956578df7804a3c90b80fdc
- affected>= 368ba06881c395f1c9a7ba22203cf8d78b4addc0 and < b62c510f59803f82f9b4c76ead2a56833b2984c7
- affected>= 368ba06881c395f1c9a7ba22203cf8d78b4addc0 and < cfc0b8e5080aec87700774e8568765eaa4b7b92b
- affectede9cb7be2fcbaee9e808b729e92948d38d52e5add
- affected>= 5.15.145 and < 5.15.217
- affected>= 6.1.34 and < 6.1.184
- affected>= 6.3.8 and < 6.4
- affected6.4
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.