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NVD / CVE Program· CNA Linux

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

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 07e0ab81df1790afa35732a4e8e07ff831b29008, 1c6267a1d5cf4c73b656f8181b310cbbb3e4767b, 297243e365fc9fe2f8e9b7dd535a65d922cd108b; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1.

Low priority for now. Upgrade to Linux Linux 07e0ab81df1790afa35732a4e8e07ff831b29008, 1c6267a1d5cf4c73b656f8181b310cbbb3e4767b, 297243e365fc9fe2f8e9b7dd535a65d922cd108b; azl3 kernel 6.6.144.1-1 on Azure Linux 3.0 6.6.145.2-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
Jul 25, 2026
Updated
Sep 8, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.19 and later · before 5.10.261
  • linux linux kernel5.11 and later · before 5.15.212
  • linux linux kernel5.16 and later · before 6.1.178
  • linux linux kernel6.2 and later · before 6.6.145
  • linux linux kernel6.7 and later · before 6.12.96
  • linux linux kernel6.13 and later · before 6.18.39
  • linux linux kernel6.19 and later · before 7.1.4

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.19affected
    • b24df3e30cbf48255db866720fb71f14bf9d2f39 and later · before 94e4f672db029414b9888b5137a7559f1febf2d8affected · git
    • b24df3e30cbf48255db866720fb71f14bf9d2f39 and later · before 68fc0b6cc03ca58060c0f36454e169f5fe258974affected · git
    • b24df3e30cbf48255db866720fb71f14bf9d2f39 and later · before 07e0ab81df1790afa35732a4e8e07ff831b29008affected · git
    • b24df3e30cbf48255db866720fb71f14bf9d2f39 and later · before 9136a08dc29328edd9867f2545e73906ac9df93baffected · git
    • b24df3e30cbf48255db866720fb71f14bf9d2f39 and later · before 67097772df7791c53d608f04bd31c676ccf79b83affected · git
    • b24df3e30cbf48255db866720fb71f14bf9d2f39 and later · before 297243e365fc9fe2f8e9b7dd535a65d922cd108baffected · git
    • b24df3e30cbf48255db866720fb71f14bf9d2f39 and later · before 927d4805aea0a287d36dd4f826ee24d69a2afee3affected · git
    • b24df3e30cbf48255db866720fb71f14bf9d2f39 and later · before 1c6267a1d5cf4c73b656f8181b310cbbb3e4767baffected · git
    • before 4.19not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.180-16.1.180-1
Debian:12linux-6.12before 6.12.100-1~deb12u16.12.100-1~deb12u1
Debian:13linuxbefore 6.12.96-16.12.96-1
Debian:14linuxbefore 7.1.4-17.1.4-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-64373Jul 25, 2026 · cpufreq: Fix hotplug-suspend race during reboot
    18Monitor
  • ← EarlierCVE-2026-64376Jul 25, 2026 · firmware_loader: fix device reference leak in firmware_upload_register()
    22Monitor
  • Later →CVE-2026-64390Jul 25, 2026 · ksmbd: track the connection owning a byte-range lock
    35Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux07e0ab81df1790afa35732a4e8e07ff831b29008Vendor (CNA)
Linux Linux1c6267a1d5cf4c73b656f8181b310cbbb3e4767bVendor (CNA)
Linux Linux297243e365fc9fe2f8e9b7dd535a65d922cd108bVendor (CNA)
Linux Linux67097772df7791c53d608f04bd31c676ccf79b83Vendor (CNA)
Linux Linux68fc0b6cc03ca58060c0f36454e169f5fe258974Vendor (CNA)
Linux Linux9136a08dc29328edd9867f2545e73906ac9df93bVendor (CNA)
Linux Linux927d4805aea0a287d36dd4f826ee24d69a2afee3Vendor (CNA)
Linux Linux94e4f672db029414b9888b5137a7559f1febf2d8Vendor (CNA)
azl3 kernel 6.6.144.1-1 on Azure Linux 3.06.6.145.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.180-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.100-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records