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NVD / CVE Program· CNA Linux

CVE-2025-39933: smb: client: let recv_done verify data_offset, data_length and remaining_data_length

MediumCVSS 5.5 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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: 0.34% (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 241e58de23e7c1bbb9bee526c17d9a0f2a90fbad, 581fb78e0388b78911b0c920e4073737090c8b5f, f23d5c6b7540ec9b1e73a8ea3b2ae9045248d728.
  • Severity is disputed: the assigning authority (CNA) scores it 9.4, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 241e58de23e7c1bbb9bee526c17d9a0f2a90fbad, 581fb78e0388b78911b0c920e4073737090c8b5f, f23d5c6b7540ec9b1e73a8ea3b2ae9045248d728 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: let recv_done verify data_offset, data_length and remaining_data_length This is inspired by the related server fixes.

Published
Oct 4, 2025
Updated
Oct 30, 2026
EPSS
0.3% · 28th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.3%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
5.5
CNA · Linux
9.4
3.9 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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

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Follow CVE-2025-39933

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  • when exploit code appears or is weaponized
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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

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

    • 4.16affected
    • f198186aa9bbd60fae7a2061f4feec614d880299 and later · before fdc23a47be015fba915c4f9dfd43c65ad4829a35affected · git
    • f198186aa9bbd60fae7a2061f4feec614d880299 and later · before f23d5c6b7540ec9b1e73a8ea3b2ae9045248d728affected · git
    • f198186aa9bbd60fae7a2061f4feec614d880299 and later · before 241e58de23e7c1bbb9bee526c17d9a0f2a90fbadaffected · git
    • f198186aa9bbd60fae7a2061f4feec614d880299 and later · before 581fb78e0388b78911b0c920e4073737090c8b5faffected · git
    • f198186aa9bbd60fae7a2061f4feec614d880299 and later · before f57e53ea252363234f86674db475839e5b87102eaffected · git
    • before 4.16not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.160 and later · up to and including 6.6.*not affected · semver
    • 6.12.114 and later · up to and including 6.12.*not affected · semver

Affected versions

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

  • linux linux kernel4.16 and later · before 6.16.9
  • linux linux kernel6.17

Package-level exposure

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

EcosystemPackageAffected rangeFix
AlmaLinux:10kernel-abi-stablelistsbefore 6.12.0-124.35.1.el10_16.12.0-124.35.1.el10_1
AlmaLinux:10kernel-docbefore 6.12.0-124.35.1.el10_16.12.0-124.35.1.el10_1
AlmaLinux:8bpftoolbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernelbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-abi-stablelistsbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-corebefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-cross-headersbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-debugbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-debug-corebefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-debug-develbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-debug-modulesbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-debug-modules-extrabefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-develbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-docbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-headersbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-modulesbefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-modules-extrabefore 4.18.0-553.94.1.el8_104.18.0-553.94.1.el8_10
AlmaLinux:8kernel-rtbefore 4.18.0-553.94.1.rt7.435.el8_104.18.0-553.94.1.rt7.435.el8_10
AlmaLinux:8kernel-rt-corebefore 4.18.0-553.94.1.rt7.435.el8_104.18.0-553.94.1.rt7.435.el8_10
AlmaLinux:8kernel-rt-debugbefore 4.18.0-553.94.1.rt7.435.el8_104.18.0-553.94.1.rt7.435.el8_10
AlmaLinux:8kernel-rt-debug-corebefore 4.18.0-553.94.1.rt7.435.el8_104.18.0-553.94.1.rt7.435.el8_10
AlmaLinux:8kernel-rt-debug-develbefore 4.18.0-553.94.1.rt7.435.el8_104.18.0-553.94.1.rt7.435.el8_10
AlmaLinux:8kernel-rt-debug-modulesbefore 4.18.0-553.94.1.rt7.435.el8_104.18.0-553.94.1.rt7.435.el8_10
AlmaLinux:8kernel-rt-debug-modules-extrabefore 4.18.0-553.94.1.rt7.435.el8_104.18.0-553.94.1.rt7.435.el8_10

+96

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-2025-39931Oct 4, 2025 · crypto: af_alg - Set merge to zero early in af_alg_sendmsg
    22Monitor
  • ← EarlierCVE-2025-39932Oct 4, 2025 · smb: client: let smbd_destroy() call disable_work_sync(&info->post_send_credits_work)
    22Monitor
  • Later →CVE-2025-39934Oct 4, 2025 · drm: bridge: anx7625: Fix NULL pointer dereference with early IRQ
    22Monitor

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 Linux241e58de23e7c1bbb9bee526c17d9a0f2a90fbadVendor (CNA)
Linux Linux581fb78e0388b78911b0c920e4073737090c8b5fVendor (CNA)
Linux Linuxf23d5c6b7540ec9b1e73a8ea3b2ae9045248d728Vendor (CNA)
Linux Linuxf57e53ea252363234f86674db475839e5b87102eVendor (CNA)
Linux Linuxfdc23a47be015fba915c4f9dfd43c65ad4829a35Vendor (CNA)
almalinux:bpftool4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-abi-stablelists4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-core4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-cross-headers4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-core4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-devel4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-debug-modules-extra4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-devel4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
almalinux:kernel-doc4.18.0-553.94.1.el8_10 · AlmaLinux:8Package registry (OSV)
debian:linux6.12.115-2 · Debian:13Package registry (OSV)
debian:linux6.16.9-1 · Debian:14Package registry (OSV)
red hat:bpftool0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-abi-stablelists0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-core0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-core0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-devel0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-modules0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-debug-modules-extra0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-devel0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)
red hat:kernel-doc0:4.18.0-553.94.1.el8_10 · Red Hat:enterprise_linux:8::baseosPackage registry (OSV)

+3

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.

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · variant or chain candidate · public bounty program.

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

Weakness class (CWE)

—

CVSS vector

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

References

Show all references (4 more)

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

All records