NVD / CVE Program· CNA Linux

CVE-2024-35865: smb: client: fix potential UAF in smb2_is_valid_oplock_break()

Noroxi assessment

Priority: Monitor (action score 39/100)

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: 0.63% (FIRST EPSS); higher than 50.2% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
Fixed version: Linux Linux 21fed37d2bdcde33453faf61d3d4d96c355f04bd, 22863485a4626ec6ecf297f4cc0aef709bc862e4, 3.13.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 21fed37d2bdcde33453faf61d3d4d96c355f04bd, 22863485a4626ec6ecf297f4cc0aef709bc862e4, 3.13 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 potential UAF in smb2_is_valid_oplock_break() Skip sessions that are being teared down (status == SES_EXITING) to avoid UAF.

CriticalCVSS 9.8 · v3.1—No exploit Fix available

BDU:2024-04222

Published: May 19, 2024
Updated: Aug 5, 2026
EPSS: 0.6% · 50th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.6%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · Linux: 9.8; 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

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

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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 6.1.85
linux linux kernel6.2 and later · before 6.6.26
linux linux kernel6.7 and later · before 6.8.5
linux linux kernel6.9

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
- a67172a013953664b1dad03c648200c70b90506c, 3.13affected
- 7f48558e6489d032b1584b0cc9ac4bb11072c034 and later · before a710ef9e974f18232d2b9b19c90eda1a1167b2d4affected · git
- 7f48558e6489d032b1584b0cc9ac4bb11072c034 and later · before 84488466b7a69570bdbf76dd9576847ab97d54e7affected · git
- 7f48558e6489d032b1584b0cc9ac4bb11072c034 and later · before 21fed37d2bdcde33453faf61d3d4d96c355f04bdaffected · git
- 7f48558e6489d032b1584b0cc9ac4bb11072c034 and later · before 3dba0e5276f131e36d6d8043191d856f49238628affected · git
- 7f48558e6489d032b1584b0cc9ac4bb11072c034 and later · before 22863485a4626ec6ecf297f4cc0aef709bc862e4affected · git
- 3.12.48 and later · before 3.13affected · semver
- before 3.13not affected · semver
- 5.15.209 and later · up to and including 5.15.*not affected · semver
- 6.1.85 and later · up to and including 6.1.*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 6.1.85-1	6.1.85-1
Debian:13	linux	before 6.8.9-1	6.8.9-1

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-2024-35863May 19, 2024 · smb: client: fix potential UAF in is_valid_oplock_break()
31Monitor
← EarlierCVE-2024-35864May 19, 2024 · smb: client: fix potential UAF in smb2_is_valid_lease_break()
31Monitor
Later →CVE-2024-35866May 19, 2024 · smb: client: fix potential UAF in cifs_dump_full_key()
31Monitor

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	21fed37d2bdcde33453faf61d3d4d96c355f04bd	Vendor (CNA)
Linux Linux	22863485a4626ec6ecf297f4cc0aef709bc862e4	Vendor (CNA)
Linux Linux	3.13	Vendor (CNA)
Linux Linux	3dba0e5276f131e36d6d8043191d856f49238628	Vendor (CNA)
Linux Linux	84488466b7a69570bdbf76dd9576847ab97d54e7	Vendor (CNA)
Linux Linux	a710ef9e974f18232d2b9b19c90eda1a1167b2d4	Vendor (CNA)
debian:linux	6.1.85-1 · 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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-24-0506 · May 20, 2024(Linux Kernel Güncellemesi)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
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: None
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:N/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, 10:08 PM UTC

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

References

git.kernel.org/stable/c/21fed37d2bdcde33453faf61d3d4d96c355f04bd

Show all references (4 more)

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

All records