VulnerabilityPublished 25 Jul 2026Updated 6 Nov 2026

CVE-2026-64381: Linux kernel · smb: client: Fix next buffer leak in receive_encrypted_standard()

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in 67097772df7791c53d608f04bd31c676ccf79b83 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 17:04 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in 67097772df7791c53d608f04bd31c676ccf79b83, 297243e365fc9fe2f8e9b7dd535a65d922cd108b, 9136a08dc29328edd9867f2545e73906ac9df93b +5

Exploitation evidence

Disclosed: evidence found.
CVE published 25 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ b24df3e30cbf48255db866720fb71f14bf9d2f39, < 67097772df7791c53d608f04bd31c676ccf79b83	Fixed in 67097772df7791c53d608f04bd31c676ccf79b83
LinuxLinux	Affected ≥ b24df3e30cbf48255db866720fb71f14bf9d2f39, < 297243e365fc9fe2f8e9b7dd535a65d922cd108b	Fixed in 297243e365fc9fe2f8e9b7dd535a65d922cd108b
LinuxLinux	Affected ≥ b24df3e30cbf48255db866720fb71f14bf9d2f39, < 9136a08dc29328edd9867f2545e73906ac9df93b	Fixed in 9136a08dc29328edd9867f2545e73906ac9df93b
LinuxLinux	Affected ≥ b24df3e30cbf48255db866720fb71f14bf9d2f39, < 927d4805aea0a287d36dd4f826ee24d69a2afee3	Fixed in 927d4805aea0a287d36dd4f826ee24d69a2afee3
LinuxLinux	Affected ≥ b24df3e30cbf48255db866720fb71f14bf9d2f39, < 94e4f672db029414b9888b5137a7559f1febf2d8	Fixed in 94e4f672db029414b9888b5137a7559f1febf2d8
LinuxLinux	Affected ≥ b24df3e30cbf48255db866720fb71f14bf9d2f39, < 68fc0b6cc03ca58060c0f36454e169f5fe258974	Fixed in 68fc0b6cc03ca58060c0f36454e169f5fe258974

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: Fix next buffer leak in receive_encrypted_standard() receive_encrypted_standard() allocates next_buffer before checking whether the number of compound PDUs already reached MAX_COMPOUND. If the limit check fails, the function returns immediately and the newly allocated next_buffer is not assigned to server->smallbuf/server->bigbuf, making it leaked. Move the MAX_COMPOUND check before allocating next_buffer.

References

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