CVE-2026-52936 (GCVE-0-2026-52936)
Vulnerability from cvelistv5 – Published: 2026-06-24 07:14 – Updated: 2026-06-24 07:14
VLAI
EPSS
VEX
Title
crypto: jitterentropy - replace long-held spinlock with mutex
Summary
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.
Severity
5.5 (Medium)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
bb5530e4082446aac3a3d69780cd4dbfa4520013 , < 18216b8ab6904753eaf31baf453cb02ecd202ba4
(git)
Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < 4c03e6eb98443dc4d6d422a9780034a5b75376b4 (git) Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < ff734dbd9e2432601a6dcd167cfb0bf8a36d1880 (git) Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < ec427dc5286da1ed08f2d510e2147a7581b0cb02 (git) Affected: bb5530e4082446aac3a3d69780cd4dbfa4520013 , < 01d798e9feb30212952d4e992801ba6bd6a82351 (git) |
guessed | |
| Linux | Linux |
Affected:
4.2
Unaffected: 0 , < 4.2 (semver) Unaffected: 6.6.141 , ≤ 6.6.* (semver) Unaffected: 6.12.91 , ≤ 6.12.* (semver) Unaffected: 6.18.33 , ≤ 6.18.* (semver) Unaffected: 7.0.10 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"crypto/jitterentropy-kcapi.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "18216b8ab6904753eaf31baf453cb02ecd202ba4",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
},
{
"lessThan": "4c03e6eb98443dc4d6d422a9780034a5b75376b4",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
},
{
"lessThan": "ff734dbd9e2432601a6dcd167cfb0bf8a36d1880",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
},
{
"lessThan": "ec427dc5286da1ed08f2d510e2147a7581b0cb02",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
},
{
"lessThan": "01d798e9feb30212952d4e992801ba6bd6a82351",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"crypto/jitterentropy-kcapi.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.2"
},
{
"lessThan": "4.2",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.141",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.91",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.33",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.141",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.91",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.33",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.0.10",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1",
"versionStartIncluding": "4.2",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: jitterentropy - replace long-held spinlock with mutex\n\njent_kcapi_random() serializes the shared jitterentropy state, but it\ncurrently holds a spinlock across the jent_read_entropy() call. That\npath performs expensive jitter collection and SHA3 conditioning, so\nparallel readers can trigger stalls as contending waiters spin for\nthe same lock.\n\nTo prevent non-preemptible lock hold, replace rng-\u003ejent_lock with a\nmutex so contended readers sleep instead of spinning on a shared lock\nheld across expensive entropy generation."
}
],
"providerMetadata": {
"dateUpdated": "2026-06-24T07:14:26.649Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/18216b8ab6904753eaf31baf453cb02ecd202ba4"
},
{
"url": "https://git.kernel.org/stable/c/4c03e6eb98443dc4d6d422a9780034a5b75376b4"
},
{
"url": "https://git.kernel.org/stable/c/ff734dbd9e2432601a6dcd167cfb0bf8a36d1880"
},
{
"url": "https://git.kernel.org/stable/c/ec427dc5286da1ed08f2d510e2147a7581b0cb02"
},
{
"url": "https://git.kernel.org/stable/c/01d798e9feb30212952d4e992801ba6bd6a82351"
}
],
"title": "crypto: jitterentropy - replace long-held spinlock with mutex",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-52936",
"datePublished": "2026-06-24T07:14:26.649Z",
"dateReserved": "2026-06-09T07:44:35.370Z",
"dateUpdated": "2026-06-24T07:14:26.649Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-52936",
"date": "2026-09-23",
"epss": "0.00114",
"percentile": "0.01666"
},
"microsoft_vex": {
"current_release_date": "2026-07-09T14:39:21.000Z",
"cve": "CVE-2026-52936",
"id": "msrc_CVE-2026-52936",
"initial_release_date": "2026-06-02T00:00:00.000Z",
"product_status:fixed": "1",
"product_status:known_affected": "1",
"source": "Microsoft CSAF VEX",
"status": "final",
"title": "crypto: jitterentropy - replace long-held spinlock with mutex",
"url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-52936.json",
"version": "2"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"crypto/jitterentropy-kcapi.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "18216b8ab6904753eaf31baf453cb02ecd202ba4",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
},
{
"lessThan": "4c03e6eb98443dc4d6d422a9780034a5b75376b4",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
},
{
"lessThan": "ff734dbd9e2432601a6dcd167cfb0bf8a36d1880",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
},
{
"lessThan": "ec427dc5286da1ed08f2d510e2147a7581b0cb02",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
},
{
"lessThan": "01d798e9feb30212952d4e992801ba6bd6a82351",
"status": "affected",
"version": "bb5530e4082446aac3a3d69780cd4dbfa4520013",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"crypto/jitterentropy-kcapi.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.2"
},
{
"lessThan": "4.2",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.141",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.91",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.33",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.0.*",
"status": "unaffected",
"version": "7.0.10",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"configurations": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "EF97161C-1BB5-4ADC-A7BA-2A18D7A44511",
"versionEndExcluding": "6.6.141",
"versionStartIncluding": "4.2",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "C918746B-DE6F-448F-A93E-A04C5481688D",
"versionEndExcluding": "6.12.91",
"versionStartIncluding": "6.7",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "96D99E49-380D-43AB-BDBA-25C3AD018A9C",
"versionEndExcluding": "6.18.33",
"versionStartIncluding": "6.13",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"matchCriteriaId": "A13475D2-59BF-4716-94B5-7C1D239A2CF4",
"versionEndExcluding": "7.0.10",
"versionStartIncluding": "6.19",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncrypto: jitterentropy - replace long-held spinlock with mutex\n\njent_kcapi_random() serializes the shared jitterentropy state, but it\ncurrently holds a spinlock across the jent_read_entropy() call. That\npath performs expensive jitter collection and SHA3 conditioning, so\nparallel readers can trigger stalls as contending waiters spin for\nthe same lock.\n\nTo prevent non-preemptible lock hold, replace rng-\u003ejent_lock with a\nmutex so contended readers sleep instead of spinning on a shared lock\nheld across expensive entropy generation."
}
],
"id": "CVE-2026-52936",
"lastModified": "2026-07-08T20:31:02.290",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 5.5,
"baseSeverity": "MEDIUM",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 3.6,
"source": "nvd@nist.gov",
"type": "Primary"
}
]
},
"published": "2026-06-24T08:16:23.883",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/01d798e9feb30212952d4e992801ba6bd6a82351"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/18216b8ab6904753eaf31baf453cb02ecd202ba4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/4c03e6eb98443dc4d6d422a9780034a5b75376b4"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/ec427dc5286da1ed08f2d510e2147a7581b0cb02"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"tags": [
"Patch"
],
"url": "https://git.kernel.org/stable/c/ff734dbd9e2432601a6dcd167cfb0bf8a36d1880"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Analyzed",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
],
"source": "nvd@nist.gov",
"type": "Primary"
}
]
}
},
"redhat_vex": {
"aggregate_severity": "Low",
"current_release_date": "2026-07-08T20:44:45+00:00",
"cve": "CVE-2026-52936",
"id": "CVE-2026-52936",
"initial_release_date": "2026-06-24T00:00:00+00:00",
"product_status:known_affected": "260",
"product_status:known_not_affected": "14",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: crypto: jitterentropy - replace long-held spinlock with mutex",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52936.json",
"version": "3"
},
"suse_vex": {
"aggregate_severity": "moderate",
"current_release_date": "2026-09-10T02:43:01Z",
"cve": "CVE-2026-52936",
"id": "CVE-2026-52936",
"initial_release_date": "2026-06-25T02:19:47Z",
"product_status:first_fixed": "2",
"product_status:known_affected": "699",
"product_status:known_not_affected": "21",
"product_status:recommended": "250",
"source": "SUSE CSAF VEX",
"status": "interim",
"title": "SUSE CVE CVE-2026-52936",
"url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-52936.json",
"version": "9"
}
}
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…