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NVD / CVE Program· CNA Linux

CVE-2025-37808: crypto: null - Use spin lock instead of mutex

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: 0.21% (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 0486de3c1b8223138dcc614846bd76364f758de6, 1b66a5920b7fc7cc6251192a3fcad115b6d75dd5, 1dd4a8561d85dea545cf93f56efc48df8176e218; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1; azl3 kernel 6.6.92.2-1 on Azure Linux 3.0 6.6.92.2-1.

Low priority for now. Upgrade to Linux Linux 0486de3c1b8223138dcc614846bd76364f758de6, 1b66a5920b7fc7cc6251192a3fcad115b6d75dd5, 1dd4a8561d85dea545cf93f56efc48df8176e218; azl3 kernel 6.6.85.1-4 on Azure Linux 3.0 6.6.92.2-1; azl3 kernel 6.6.92.2-1 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: crypto: null - Use spin lock instead of mutex As the null algorithm may be freed in softirq context through af_alg, use spin locks instead of mutexes to protect the default null algorithm.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
May 8, 2025
Updated
Jun 17, 2026
EPSS
0.2% · 11th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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.

Follow CVE-2025-37808

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 kernel5.5 and later · before 5.10.237
  • linux linux kernel5.11 and later · before 5.15.181
  • linux linux kernel5.16 and later · before 6.1.136
  • linux linux kernel4.2 and later · before 5.4.293
  • linux linux kernel6.7 and later · before 6.12.26
  • linux linux kernel6.13 and later · before 6.14.5
  • linux linux kernel6.2 and later · before 6.6.89

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

    • 4.2affected
    • 330234638e16b7b95e8e5e6be719a61a93f074b8 and later · before f7a5a5c8e1ec16a4b2041398abe95de0e14572efaffected · git
    • 330234638e16b7b95e8e5e6be719a61a93f074b8 and later · before e307c54ac8198bf09652c72603ba6e6d97798410affected · git
    • 330234638e16b7b95e8e5e6be719a61a93f074b8 and later · before 1dd4a8561d85dea545cf93f56efc48df8176e218affected · git
    • 330234638e16b7b95e8e5e6be719a61a93f074b8 and later · before e27244cbe10658a66b8775be7f0acc4ad2f618d6affected · git
    • 330234638e16b7b95e8e5e6be719a61a93f074b8 and later · before 1b66a5920b7fc7cc6251192a3fcad115b6d75dd5affected · git
    • 330234638e16b7b95e8e5e6be719a61a93f074b8 and later · before 0486de3c1b8223138dcc614846bd76364f758de6affected · git
    • 330234638e16b7b95e8e5e6be719a61a93f074b8 and later · before 8cf2945512a8c0ef74ddd5b5a4f6b6a2fb1a4efbaffected · git
    • 330234638e16b7b95e8e5e6be719a61a93f074b8 and later · before dcc47a028c24e793ce6d6efebfef1a1e92f80297affected · git
    • before 4.2not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.137-16.1.137-1
Debian:13linuxbefore 6.12.27-16.12.27-1

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-2025-37803May 8, 2025 · udmabuf: fix a buf size overflow issue during udmabuf creation
    31Monitor
  • ← EarlierCVE-2025-37805May 8, 2025 · sound/virtio: Fix cancel_sync warnings on uninitialized work_structs
    22Monitor
  • Later →CVE-2025-37809May 8, 2025 · usb: typec: class: Fix NULL pointer access
    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 / packageFixed versionSource
Linux Linux0486de3c1b8223138dcc614846bd76364f758de6Vendor (CNA)
Linux Linux1b66a5920b7fc7cc6251192a3fcad115b6d75dd5Vendor (CNA)
Linux Linux1dd4a8561d85dea545cf93f56efc48df8176e218Vendor (CNA)
Linux Linux8cf2945512a8c0ef74ddd5b5a4f6b6a2fb1a4efbVendor (CNA)
Linux Linuxdcc47a028c24e793ce6d6efebfef1a1e92f80297Vendor (CNA)
Linux Linuxe27244cbe10658a66b8775be7f0acc4ad2f618d6Vendor (CNA)
Linux Linuxe307c54ac8198bf09652c72603ba6e6d97798410Vendor (CNA)
Linux Linuxf7a5a5c8e1ec16a4b2041398abe95de0e14572efVendor (CNA)
azl3 kernel 6.6.85.1-4 on Azure Linux 3.06.6.92.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
azl3 kernel 6.6.92.2-1 on Azure Linux 3.06.6.92.2-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.137-1 · Debian:12Package 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
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)

—

CVSS vector

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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

References

Show all references (9 more)

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

All records