NVD / CVE Program· CNA Linux

CVE-2024-49988: ksmbd: add refcnt to ksmbd_conn struct

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: 0.61% (FIRST EPSS); higher than 50% of all records.
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 18f06bacc197d4ac9b518ad1c69999bc3d83e7aa, 9fd3cde4628bcd3549ab95061f2bab74d2ed4f3b, e9dac92f4482a382e8c0fe1bc243da5fc3526b0c; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.57.1-2; azl3 kernel 6.6.57.1-2 on Azure Linux 3.0 6.6.57.1-2.
Severity is disputed: the assigning authority (CNA) scores it 8.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 18f06bacc197d4ac9b518ad1c69999bc3d83e7aa, 9fd3cde4628bcd3549ab95061f2bab74d2ed4f3b, e9dac92f4482a382e8c0fe1bc243da5fc3526b0c; azl3 kernel 6.6.51.1-5 on Azure Linux 3.0 6.6.57.1-2; azl3 kernel 6.6.57.1-2 on Azure Linux 3.0 6.6.57.1-2 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: add refcnt to ksmbd_conn struct When sending an oplock break request, opinfo->conn is used, But freed ->conn can be used on multichannel. This patch add a reference count to the ksmbd_conn struct so that it can be freed when it is no longer used.

BDU:2025-16135

Published: Oct 21, 2024
Updated: Aug 5, 2026
EPSS: 0.6% · 50th percentile
CWE: CWE-416

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 22 / 40 · 5.5 / 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: 5.5
CNA · Linux: 8.8; 3.3 point gap

CVSS:3.1/AV:N/AC:L/PR:L/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
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.

Is your version affected? Check it

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

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 18f06bacc197d4ac9b518ad1c69999bc3d83e7aaaffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before 9fd3cde4628bcd3549ab95061f2bab74d2ed4f3baffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before e9dac92f4482a382e8c0fe1bc243da5fc3526b0caffected · git
- 0626e6641f6b467447c81dd7678a69c66f7746cf and later · before ee426bfb9d09b29987369b897fe9b6485ac2be27affected · git
- before 5.15not affected · semver
- 6.6.55 and later · up to and including 6.6.*not affected · semver
- 6.10.14 and later · up to and including 6.10.*not affected · semver
- 6.11.3 and later · up to and including 6.11.*not affected · semver
- 6.12 and laternot affected · original_commit_for_fix

Affected versions

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

linux linux kernelbefore 6.6.55
linux linux kernel6.7 and later · before 6.10.14
linux linux kernel6.11 and later · before 6.11.3

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	from 0	—
Debian:13	linux	before 6.11.4-1	6.11.4-1

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-2024-49986Oct 21, 2024 · platform/x86: x86-android-tablets: Fix use after free on platform_device_register() errors
31Monitor
← EarlierCVE-2024-49987Oct 21, 2024 · bpftool: Fix undefined behavior in qsort(NULL, 0, ...)
22Monitor
Later →CVE-2024-49989Oct 21, 2024 · drm/amd/display: fix double free issue during amdgpu module unload
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	18f06bacc197d4ac9b518ad1c69999bc3d83e7aa	Vendor (CNA)
Linux Linux	9fd3cde4628bcd3549ab95061f2bab74d2ed4f3b	Vendor (CNA)
Linux Linux	e9dac92f4482a382e8c0fe1bc243da5fc3526b0c	Vendor (CNA)
Linux Linux	ee426bfb9d09b29987369b897fe9b6485ac2be27	Vendor (CNA)
azl3 kernel 6.6.51.1-5 on Azure Linux 3.0	6.6.57.1-2 · CBL-Mariner Releases	Microsoft (MSRC)
azl3 kernel 6.6.57.1-2 on Azure Linux 3.0	6.6.57.1-2 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.11.4-1 · Debian:13	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.

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)

CWE-416 · Use After Free

CVSS vector

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

nvd-primary

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 (1)

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

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

References

git.kernel.org/stable/c/18f06bacc197d4ac9b518ad1c69999bc3d83e7aa

Show all references (3 more)

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

All records