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NVD / CVE Program· CNA Linux

CVE-2025-38561: ksmbd: fix Preauh_HashValue race condition

Noroxi assessment

Priority: Monitor (action score 18/100)

  • Public proof-of-concept code exists (GitHub); there is no record of exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.44% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. Special conditions such as timing or configuration are required.
  • Fixed version: Linux Linux 44a3059c4c8cc635a1fb2afd692d0730ca1ba4b6, 6613887da1d18dd2ecfd6c6148a873c4d903ebdc, 7d7c0c5304c88bcbd7a85e9bcd61d27e998ba5fc.
  • Severity is disputed: the assigning authority (CNA) scores it 9.8, NVD 4.7.

Low priority for now. Upgrade to Linux Linux 44a3059c4c8cc635a1fb2afd692d0730ca1ba4b6, 6613887da1d18dd2ecfd6c6148a873c4d903ebdc, 7d7c0c5304c88bcbd7a85e9bcd61d27e998ba5fc 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: ksmbd: fix Preauh_HashValue race condition If client send multiple session setup requests to ksmbd, Preauh_HashValue race condition could happen. There is no need to free sess->Preauh_HashValue at session setup phase. It can be freed together with session at connection termination phase.

MediumCVSS 4.7 · v3.1—Proof of concept Fix available
Published
Aug 19, 2025
Updated
Aug 5, 2026
EPSS
0.4% · 39th percentile

Report tools

JSON

Action score

18

Monitor

Low priority for now.

CVSS
18 / 40 · 4.7 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.4%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
4.7
CNA · Linux
9.8
5.1 point gap

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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
  • Proof of concept exists, no weaponized module
  • A fix has been released

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

Follow CVE-2025-38561

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
debiandebian linux

Affected versions

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

  • debian debian linux11.0
  • linux linux kernel5.15 and later · before 6.1.148
  • linux linux kernel6.2 and later · before 6.6.102
  • linux linux kernel6.7 and later · before 6.12.42
  • linux linux kernel6.13 and later · before 6.15.10
  • linux linux kernel6.16 and later · before 6.16.1

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

    • 5.15affected
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before fbf5c0845ed15122a770bca9be1d9b60b470d3aaaffected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before b69fd87076daa66f3d186bd421a7b0ee0cb45829affected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before edeecc7871e8fc0878d53ce286c75040a0e38f6caffected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 7d7c0c5304c88bcbd7a85e9bcd61d27e998ba5fcaffected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 6613887da1d18dd2ecfd6c6148a873c4d903ebdcaffected · git
    • 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 44a3059c4c8cc635a1fb2afd692d0730ca1ba4b6affected · git
    • before 5.15not affected · semver
    • 6.1.148 and later · up to and including 6.1.*not affected · semver
    • 6.6.102 and later · up to and including 6.6.*not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.148-16.1.148-1
Debian:13linuxbefore 6.12.43-16.12.43-1
Debian:14linuxbefore 6.16.3-16.16.3-1

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-2025-38556Aug 19, 2025 · HID: core: Harden s32ton() against conversion to 0 bits
    28Monitor
  • ← EarlierCVE-2025-38558Aug 19, 2025 · usb: gadget: uvc: Initialize frame-based format color matching descriptor
    22Monitor
  • Later →CVE-2025-38562Aug 19, 2025 · ksmbd: fix null pointer dereference error in generate_encryptionkey
    26Monitor

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 Linux44a3059c4c8cc635a1fb2afd692d0730ca1ba4b6Vendor (CNA)
Linux Linux6613887da1d18dd2ecfd6c6148a873c4d903ebdcVendor (CNA)
Linux Linux7d7c0c5304c88bcbd7a85e9bcd61d27e998ba5fcVendor (CNA)
Linux Linuxb69fd87076daa66f3d186bd421a7b0ee0cb45829Vendor (CNA)
Linux Linuxedeecc7871e8fc0878d53ce286c75040a0e38f6cVendor (CNA)
Linux Linuxfbf5c0845ed15122a770bca9be1d9b60b470d3aaVendor (CNA)
debian:linux6.1.148-1 · Debian:12Package registry (OSV)

Exploit status

Proof of concept available

A public proof of concept or detection signature exists. Exploit knowledge is out there; don't delay patching.

Evidence

  • Proof-of-concept repository on GitHub ×1

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Proof-of-concept repository on GitHubstars:02025-10-08

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.

  1. Published
  2. First PoC+49 d
  3. TodayNov 7, 2026+445 d

No history yet (it accumulates with the daily EPSS job).

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.
  • Special conditions such as timing or configuration are required.

If successful

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

Weakness class (CWE)

CWE-362 · Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSS vector

CVSS:3.1/AV:L/AC:H/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.

ATT&CK techniques

—

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