NVD / CVE Program· CNA Linux

CVE-2025-38708: drbd: add missing kref_get in handle_write_conflicts

Noroxi assessment

Priority: Monitor (action score 31/100)

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: 0.39% (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 00c9c9628b49e368d140cfa61d7df9b8922ec2a8, 0336bfe9c237476bd7c45605a36ca79c2bca62e5, 3a896498f6f577e57bf26aaa93b48c22b6d20c20; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1.
Severity is disputed: the assigning authority (CNA) scores it 9.8, NVD 7.8.

Low priority for now. Upgrade to Linux Linux 00c9c9628b49e368d140cfa61d7df9b8922ec2a8, 0336bfe9c237476bd7c45605a36ca79c2bca62e5, 3a896498f6f577e57bf26aaa93b48c22b6d20c20; azl3 kernel 6.6.96.2-2 on Azure Linux 3.0 6.6.104.2-1 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: drbd: add missing kref_get in handle_write_conflicts With `two-primaries` enabled, DRBD tries to detect "concurrent" writes and handle write conflicts, so that even if you write to the same sector simultaneously on both nodes, they end up with the identical data once the writes are completed. In handling "superseeded" writes, we forgot a kref_get, resulting in a premature drbd_destroy_device and use after free, and further to kernel crashes with symptoms. Relevance: No one should use DRBD as a random data generator, and apparently all users of "two-primaries" handle concurrent writes correctly on layer up. That is cluster file systems use some distributed lock manager, and live migration in virtualization environments stops writes on one node before starting writes on the other node. Which means that other than for "test cases", this code path is never taken in real life. FYI, in DRBD 9, things are handled differently nowadays. We still detect "write conflicts", but no longer try to be smart about them. We decided to disconnect hard instead: upper layers must not submit concurrent writes. If they do, that's their fault.

HighCVSS 7.8 · v3.1—No exploit Fix available

Memory safety

BDU:2025-15188

Published: Sep 4, 2025
Updated: Oct 19, 2026
EPSS: 0.3% · 33th percentile
CWE: CWE-416

Report tools

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Action score

Monitor

Low priority for now.

CVSS: 31 / 40 · 7.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.3%

CNA vs NVD score

NVD: 7.8
CNA · Linux: 9.8; 2.0 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
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
debian	debian linux	cpe:2.3:o:debian:debian_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 kernel5.5 and later · before 5.10.241
linux linux kernel5.11 and later · before 5.15.190
linux linux kernel5.16 and later · before 6.1.149
linux linux kernel4.5 and later · before 5.4.297
linux linux kernel6.7 and later · before 6.12.43
linux linux kernel6.13 and later · before 6.15.11
linux linux kernel6.16 and later · before 6.16.2
linux linux kernel6.2 and later · before 6.6.103

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
- 4.5affected
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 0336bfe9c237476bd7c45605a36ca79c2bca62e5affected · git
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 810cd546a29bfac90ed1328ea01d693d4bd11cb1affected · git
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 84ef8dd3238330d1795745ece83b19f0295751bfaffected · git
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 57418de35420cedab035aa1da8a26c0499b7f575affected · git
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 9f53b2433ad248cd3342cc345f56f5c7904bd8c4affected · git
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 7d483ad300fc0a06f69b019dda8f74970714baf8affected · git
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 46e3763dcae0ffcf8fcfaff4fc10a90a92ffdd89affected · git
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 3a896498f6f577e57bf26aaa93b48c22b6d20c20affected · git
- 668700b40a7c8727bbd2b3fd4fd22e0ce3f1aeb6 and later · before 00c9c9628b49e368d140cfa61d7df9b8922ec2a8affected · git

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 6.1.153-1	6.1.153-1
Debian:13	linux	before 6.12.43-1	6.12.43-1
Debian:14	linux	before 6.16.3-1	6.16.3-1

Same product

linux: all records

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Published before and after this one in the same product

← EarlierCVE-2025-38706Sep 4, 2025 · ASoC: core: Check for rtd == NULL in snd_soc_remove_pcm_runtime()
22Monitor
← EarlierCVE-2025-38707Sep 4, 2025 · fs/ntfs3: Add sanity check for file name
31Monitor
Later →CVE-2025-38709Sep 4, 2025 · loop: Avoid updating block size under exclusive owner
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	00c9c9628b49e368d140cfa61d7df9b8922ec2a8	Vendor (CNA)
Linux Linux	0336bfe9c237476bd7c45605a36ca79c2bca62e5	Vendor (CNA)
Linux Linux	3a896498f6f577e57bf26aaa93b48c22b6d20c20	Vendor (CNA)
Linux Linux	46e3763dcae0ffcf8fcfaff4fc10a90a92ffdd89	Vendor (CNA)
Linux Linux	57418de35420cedab035aa1da8a26c0499b7f575	Vendor (CNA)
Linux Linux	7d483ad300fc0a06f69b019dda8f74970714baf8	Vendor (CNA)
Linux Linux	810cd546a29bfac90ed1328ea01d693d4bd11cb1	Vendor (CNA)
Linux Linux	84ef8dd3238330d1795745ece83b19f0295751bf	Vendor (CNA)
Linux Linux	9f53b2433ad248cd3342cc345f56f5c7904bd8c4	Vendor (CNA)
azl3 kernel 6.6.96.2-2 on Azure Linux 3.0	6.6.104.2-1 · CBL-Mariner Releases	Microsoft (MSRC)
debian:linux	6.1.153-1 · 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

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: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Local
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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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

Fix✗ → ✓Sep 28, 2026, 10:11 PM UTC

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

References

git.kernel.org/stable/c/00c9c9628b49e368d140cfa61d7df9b8922ec2a8

Show all references (12 more)

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

All records