CVE-2026-52936

System stall via jitterentropy spinlock contention

Published Jun 24, 2026 · Updated Jun 24, 2026

Denial of service in the Linux Kernel allows local users to stall the system through concurrent reads from the jitterentropy RNG. jent_kcapi_random() holds rng->jent_lock as a spinlock while jent_read_entropy() performs expensive jitter collection and SHA3 conditioning. Local low-privileged access and parallel entropy requests are required, and contending readers can leave processors spinning long enough to interrupt service.

CVSS severity5.5
Medium
EPSS probability0.11%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux Kernel allows local users to stall the system through concurrent reads from the jitterentropy RNG. jent_kcapi_random() holds rng->jent_lock as a spinlock while jent_read_entropy() performs expensive jitter collection and SHA3 conditioning. Local low-privileged access and parallel entropy requests are required, and contending readers can leave processors spinning long enough to interrupt service.

The record

CVE
CVE-2026-52936
Published
Jun 24, 2026
Updated
Jun 24, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=4.2
  2. Affected versionversion=bb5530e4082446aac3a3d69780cd4dbfa4520013 <01d798e9feb30212952d4e992801ba6bd6a82351
  3. Affected versionversion=bb5530e4082446aac3a3d69780cd4dbfa4520013 <18216b8ab6904753eaf31baf453cb02ecd202ba4
  4. Affected versionversion=bb5530e4082446aac3a3d69780cd4dbfa4520013 <4c03e6eb98443dc4d6d422a9780034a5b75376b4
  5. Affected versionversion=bb5530e4082446aac3a3d69780cd4dbfa4520013 <ec427dc5286da1ed08f2d510e2147a7581b0cb02
  6. Affected versionversion=bb5530e4082446aac3a3d69780cd4dbfa4520013 <ff734dbd9e2432601a6dcd167cfb0bf8a36d1880

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.2; version=bb5530e4082446aac3a3d69780cd4dbfa4520013 <01d798e9feb30212952d4e992801ba6bd6a82351; version=bb5530e4082446aac3a3d69780cd4dbfa4520013 <18216b8ab6904753eaf31baf453cb02ecd202ba4; version=bb5530e4082446aac3a3d69780cd4dbfa4520013 <4c03e6eb98443dc4d6d422a9780034a5b75376b4; version=bb5530e4082446aac3a3d69780cd4dbfa4520013 <ec427dc5286da1ed08f2d510e2147a7581b0cb02; version=bb5530e4082446aac3a3d69780cd4dbfa4520013 <ff734dbd9e2432601a6dcd167cfb0bf8a36d1880

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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