NVD / CVE Program· CNA Linux

CVE-2025-22041: ksmbd: fix use-after-free in ksmbd_sessions_deregister()

Noroxi assessment

Priority: Monitor (action score 35/100)

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: 0.69% (FIRST EPSS); higher than 53.1% of all records.
Anyone who can reach it over the internet 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 15a9605f8d69dc85005b1a00c31a050b8625e1aa, 33cc29e221df7a3085ae413e8c26c4e81a151153, 8ed0e9d2f410f63525afb8351181eea36c80bcf1; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1.

Low priority for now. Upgrade to Linux Linux 15a9605f8d69dc85005b1a00c31a050b8625e1aa, 33cc29e221df7a3085ae413e8c26c4e81a151153, 8ed0e9d2f410f63525afb8351181eea36c80bcf1; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1 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: ksmbd: fix use-after-free in ksmbd_sessions_deregister() In multichannel mode, UAF issue can occur in session_deregister when the second channel sets up a session through the connection of the first channel. session that is freed through the global session table can be accessed again through ->sessions of connection.

HighCVSS 8.8 · v3.1—No exploit Fix available

Memory safety

Published: Apr 16, 2025
Updated: Aug 5, 2026
EPSS: 0.6% · 53th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 8.8; NVD has not scored this yet; the score shown is the CNA’s.

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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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.

Vendor	Product	CPE
linux	linux kernel	cpe:2.3:o:linux:linux_kernel

Affected versions

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

linux linux kernelbefore 6.1.134
linux linux kernel6.2 and later · before 6.6.87
linux linux kernel6.7 and later · before 6.12.13
linux linux kernel6.13 and later · before 6.13.11
linux linux kernel6.14 and later · before 6.14.2

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 f0eb3f575138b816da74697bd506682574742fcdaffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before a8a8ae303a8395cbac270b5b404d85df6ec788f8affected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before ca042cc0e4f9e0d2c8f86dd67e4b22f30a516a9baffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 8ed0e9d2f410f63525afb8351181eea36c80bcf1affected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 33cc29e221df7a3085ae413e8c26c4e81a151153affected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 15a9605f8d69dc85005b1a00c31a050b8625e1aaaffected · git
- before 5.15not affected · semver
- 6.1.134 and later · up to and including 6.1.*not affected · semver
- 6.6.87 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.

Ecosystem	Package	Affected range	Fix
Debian:12	linux	before 6.1.135-1	6.1.135-1
Debian:13	linux	before 6.12.25-1	6.12.25-1

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-2025-22039Apr 16, 2025 · ksmbd: fix overflow in dacloffset bounds check
28Monitor
← EarlierCVE-2025-22040Apr 16, 2025 · ksmbd: fix session use-after-free in multichannel connection
35Monitor
Later →CVE-2025-22042Apr 16, 2025 · ksmbd: add bounds check for create lease context
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 / package	Fixed version	Source
Linux Linux	15a9605f8d69dc85005b1a00c31a050b8625e1aa	Vendor (CNA)
Linux Linux	33cc29e221df7a3085ae413e8c26c4e81a151153	Vendor (CNA)
Linux Linux	8ed0e9d2f410f63525afb8351181eea36c80bcf1	Vendor (CNA)
Linux Linux	a8a8ae303a8395cbac270b5b404d85df6ec788f8	Vendor (CNA)
Linux Linux	ca042cc0e4f9e0d2c8f86dd67e4b22f30a516a9b	Vendor (CNA)
Linux Linux	f0eb3f575138b816da74697bd506682574742fcd	Vendor (CNA)
azl3 kernel 6.6.85.1-4 on Azure Linux 3.0	6.6.92.2-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.135-1 · Debian:12	Package 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.

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

Anyone who can reach it over the internet 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: Network
Attack complexity: Low
Privileges required: Low
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-416 · Use After Free

CVSS vector

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

nvd-secondary

Root cause

After a memory region is freed, another reference pointing to it is still used. By then, the same region may have been allocated for different data.

The bug in code

The whole CWE-416 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1free(dev->buf);
2/* ... another thread is still running ... */
3process(dev->buf);

Fixed

1lock(&dev->lock);
2free(dev->buf);
3dev->buf = NULL;
4unlock(&dev->lock);

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

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

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

References

git.kernel.org/stable/c/15a9605f8d69dc85005b1a00c31a050b8625e1aa

Show all references (6 more)

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

All records