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NVD / CVE Program· CNA Linux

CVE-2026-52936: crypto: jitterentropy - replace long-held spinlock with mutex

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: 0.11% (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 01d798e9feb30212952d4e992801ba6bd6a82351, 18216b8ab6904753eaf31baf453cb02ecd202ba4, 21de77d06f6b540e870e64ef5ff56be4eb8ba08f; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.143.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 01d798e9feb30212952d4e992801ba6bd6a82351, 18216b8ab6904753eaf31baf453cb02ecd202ba4, 21de77d06f6b540e870e64ef5ff56be4eb8ba08f; azl3 kernel 6.6.139.1-1 on Azure Linux 3.0 6.6.143.1-1 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: jitterentropy - replace long-held spinlock with mutex jent_kcapi_random() serializes the shared jitterentropy state, but it currently holds a spinlock across the jent_read_entropy() call. That path performs expensive jitter collection and SHA3 conditioning, so parallel readers can trigger stalls as contending waiters spin for the same lock. To prevent non-preemptible lock hold, replace rng->jent_lock with a mutex so contended readers sleep instead of spinning on a shared lock held across expensive entropy generation.

Published
Jun 24, 2026
Updated
Nov 6, 2026
EPSS
0.1% · 1th 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 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

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-2026-52936

When you'll hear from us

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  • 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

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
    • bb5530e4082446aac3a3d69780cd4dbfa4520013 and later · before 21de77d06f6b540e870e64ef5ff56be4eb8ba08faffected · git
    • bb5530e4082446aac3a3d69780cd4dbfa4520013 and later · before 18216b8ab6904753eaf31baf453cb02ecd202ba4affected · git
    • bb5530e4082446aac3a3d69780cd4dbfa4520013 and later · before 4c03e6eb98443dc4d6d422a9780034a5b75376b4affected · git
    • bb5530e4082446aac3a3d69780cd4dbfa4520013 and later · before ff734dbd9e2432601a6dcd167cfb0bf8a36d1880affected · git
    • bb5530e4082446aac3a3d69780cd4dbfa4520013 and later · before ec427dc5286da1ed08f2d510e2147a7581b0cb02affected · git
    • bb5530e4082446aac3a3d69780cd4dbfa4520013 and later · before 01d798e9feb30212952d4e992801ba6bd6a82351affected · git
    • before 4.2not affected · semver
    • 6.1.191 and later · up to and including 6.1.*not affected · semver
    • 6.6.141 and later · up to and including 6.6.*not affected · semver
Affected versions · NVD (4)

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

  • linux linux kernel4.2 and later · before 6.6.141
  • linux linux kernel6.7 and later · before 6.12.91
  • linux linux kernel6.13 and later · before 6.18.33
  • linux linux kernel6.19 and later · before 7.0.10

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:13linuxbefore 6.12.94-16.12.94-1
Debian:14linuxbefore 7.0.10-17.0.10-1

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-2026-52933Jun 24, 2026 · io_uring/poll: fix signed comparison in io_poll_get_ownership()
    31Monitor
  • ← EarlierCVE-2026-52935Jun 24, 2026 · xfrm: espintcp: do not reuse an in-progress partial send
    31Monitor
  • Later →CVE-2026-52937Jun 24, 2026 · tap: fix stack info leak in tap_ioctl() SIOCGIFHWADDR
    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 Linux01d798e9feb30212952d4e992801ba6bd6a82351Vendor (CNA)
Linux Linux18216b8ab6904753eaf31baf453cb02ecd202ba4Vendor (CNA)
Linux Linux21de77d06f6b540e870e64ef5ff56be4eb8ba08fVendor (CNA)
Linux Linux4c03e6eb98443dc4d6d422a9780034a5b75376b4Vendor (CNA)
Linux Linuxec427dc5286da1ed08f2d510e2147a7581b0cb02Vendor (CNA)
Linux Linuxff734dbd9e2432601a6dcd167cfb0bf8a36d1880Vendor (CNA)
azl3 kernel 6.6.139.1-1 on Azure Linux 3.06.6.143.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.12.94-1 · Debian:13Package 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.

National notice (Türkiye Cybersecurity Directorate / USOM)

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

All national notices →

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)

—

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.

References

Show all references (5 more)

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

All records