CVE-2026-8798 (GCVE-0-2026-8798)
Vulnerability from cvelistv5 – Published: 2026-08-08 00:50 – Updated: 2026-08-10 18:23
VLAI
EPSS
VEX
Title
Native entropy source retries the CPU entropy instructions without limit
Summary
In Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.1.3, the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound. RDSEED and RDRAND report failure through their carry flag, and the JNI seeding routine spun re-issuing the instruction for as long as that flag stayed clear, so a persistent failure of the on-chip entropy source - whether from a hardware fault, from the underlying DRBG being exhausted by contention across many cores, or from a hypervisor that does not provide the instruction - left the calling thread looping indefinitely inside the JNI call, where it could be neither interrupted nor timed out. Any operation drawing from the native entropy source could therefore hang, denying service to the application. The retry loops are now bounded (200 attempts for RDSEED and 20 for RDRAND, twice the baselines given in Intel's Digital Random Number Generator software implementation guide), pausing between attempts and, on exhaustion, clearing any partially written buffer and throwing rather than continuing to spin. The clear is performed by an un-elidable memzero, which uses a volatile pointer and an assembly memory barrier so that a compiler cannot optimise the erase away as a dead store. Bouncy Castle for Java (bcprov) is not affected, as it has no native entropy source; the 1.0.X and 2.0.X FIPS series are not affected.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-10 16:25 UTC
CWE
- CWE-835 - Loop with Unreachable Exit Condition ('Infinite Loop')
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/bcgit/bc-java/wiki/CVE%E2%80%9… | vendor-advisory |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Legion of the Bouncy Castle Inc. | BC-FJA |
Affected:
2.1.0 , < 2.1.3
(maven)
|
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-8798",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-10T16:25:32.762419Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-10T18:23:28.568Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://www.bouncycastle.org/download/bouncy-castle-java-fips/",
"defaultStatus": "unaffected",
"packageName": "bc-fips",
"packageURL": "pkg:maven/org.bouncycastle/bc-fips",
"platforms": [
"x86",
"x86-64"
],
"product": "BC-FJA",
"programFiles": [
"rand_jni.c",
"NativeEntropySource"
],
"vendor": "Legion of the Bouncy Castle Inc.",
"versions": [
{
"lessThan": "2.1.3",
"status": "affected",
"version": "2.1.0",
"versionType": "maven"
}
]
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eIn Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.1.3, the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound. RDSEED and RDRAND report failure through their carry flag, and the JNI seeding routine spun re-issuing the instruction for as long as that flag stayed clear, so a persistent failure of the on-chip entropy source - whether from a hardware fault, from the underlying DRBG being exhausted by contention across many cores, or from a hypervisor that does not provide the instruction - left the calling thread looping indefinitely inside the JNI call, where it could be neither interrupted nor timed out. Any operation drawing from the native entropy source could therefore hang, denying service to the application. The retry loops are now bounded (200 attempts for RDSEED and 20 for RDRAND, twice the baselines given in Intel\u0027s Digital Random Number Generator software implementation guide), pausing between attempts and, on exhaustion, clearing any partially written buffer and throwing rather than continuing to spin. The clear is performed by an un-elidable memzero, which uses a volatile pointer and an assembly memory barrier so that a compiler cannot optimise the erase away as a dead store. Bouncy Castle for Java (bcprov) is not affected, as it has no native entropy source; the 1.0.X and 2.0.X FIPS series are not affected.\u003c/p\u003e"
}
],
"value": "In Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.1.3, the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound. RDSEED and RDRAND report failure through their carry flag, and the JNI seeding routine spun re-issuing the instruction for as long as that flag stayed clear, so a persistent failure of the on-chip entropy source - whether from a hardware fault, from the underlying DRBG being exhausted by contention across many cores, or from a hypervisor that does not provide the instruction - left the calling thread looping indefinitely inside the JNI call, where it could be neither interrupted nor timed out. Any operation drawing from the native entropy source could therefore hang, denying service to the application. The retry loops are now bounded (200 attempts for RDSEED and 20 for RDRAND, twice the baselines given in Intel\u0027s Digital Random Number Generator software implementation guide), pausing between attempts and, on exhaustion, clearing any partially written buffer and throwing rather than continuing to spin. The clear is performed by an un-elidable memzero, which uses a volatile pointer and an assembly memory barrier so that a compiler cannot optimise the erase away as a dead store. Bouncy Castle for Java (bcprov) is not affected, as it has no native entropy source; the 1.0.X and 2.0.X FIPS series are not affected."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "AMBER",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/U:Amber",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-835",
"description": "CWE-835 Loop with Unreachable Exit Condition (\u0027Infinite Loop\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-08T00:50:56.956Z",
"orgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
"shortName": "bcorg"
},
"references": [
{
"tags": [
"vendor-advisory"
],
"url": "https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%908798"
}
],
"source": {
"discovery": "INTERNAL"
},
"title": "Native entropy source retries the CPU entropy instructions without limit",
"x_generator": {
"engine": "bc release-notes template"
}
}
},
"cveMetadata": {
"assignerOrgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
"assignerShortName": "bcorg",
"cveId": "CVE-2026-8798",
"datePublished": "2026-08-08T00:50:56.956Z",
"dateReserved": "2026-05-18T01:17:23.058Z",
"dateUpdated": "2026-08-10T18:23:28.568Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-8798",
"date": "2026-11-01",
"epss": "0.00428",
"percentile": "0.3706"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"collectionURL": "https://www.bouncycastle.org/download/bouncy-castle-java-fips/",
"defaultStatus": "unaffected",
"packageName": "bc-fips",
"packageURL": "pkg:maven/org.bouncycastle/bc-fips",
"platforms": [
"x86",
"x86-64"
],
"product": "BC-FJA",
"programFiles": [
"rand_jni.c",
"NativeEntropySource"
],
"vendor": "Legion of the Bouncy Castle Inc.",
"versions": [
{
"lessThan": "2.1.3",
"status": "affected",
"version": "2.1.0",
"versionType": "maven"
}
]
}
],
"source": "91579145-5d7b-4cc5-b925-a0262ff19630"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.1.3, the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound. RDSEED and RDRAND report failure through their carry flag, and the JNI seeding routine spun re-issuing the instruction for as long as that flag stayed clear, so a persistent failure of the on-chip entropy source - whether from a hardware fault, from the underlying DRBG being exhausted by contention across many cores, or from a hypervisor that does not provide the instruction - left the calling thread looping indefinitely inside the JNI call, where it could be neither interrupted nor timed out. Any operation drawing from the native entropy source could therefore hang, denying service to the application. The retry loops are now bounded (200 attempts for RDSEED and 20 for RDRAND, twice the baselines given in Intel\u0027s Digital Random Number Generator software implementation guide), pausing between attempts and, on exhaustion, clearing any partially written buffer and throwing rather than continuing to spin. The clear is performed by an un-elidable memzero, which uses a volatile pointer and an assembly memory barrier so that a compiler cannot optimise the erase away as a dead store. Bouncy Castle for Java (bcprov) is not affected, as it has no native entropy source; the 1.0.X and 2.0.X FIPS series are not affected."
},
{
"lang": "es",
"value": "En Bouncy Castle para Java FIPS (BC-FJA) antes de bc-fips 2.1.3, la fuente de entrop\u00eda nativa utilizada en plataformas Intel reintentaba las instrucciones de entrop\u00eda de la CPU sin l\u00edmite alguno. RDSEED y RDRAND informan de fallos a trav\u00e9s de su bandera de acarreo, y la rutina de siembra JNI segu\u00eda reemitiendo la instrucci\u00f3n mientras esa bandera permaneciera clara, por lo que un fallo persistente de la fuente de entrop\u00eda en el chip -ya sea por un fallo de hardware, por el agotamiento del DRBG subyacente debido a la contenci\u00f3n entre muchos n\u00facleos, o por un hipervisor que no proporciona la instrucci\u00f3n- dejaba el hilo llamador en un bucle indefinido dentro de la llamada JNI, donde no pod\u00eda ser ni interrumpido ni se le pod\u00eda agotar el tiempo de espera. Cualquier operaci\u00f3n que se nutriese de la fuente de entrop\u00eda nativa pod\u00eda, por lo tanto, colgarse, denegando el servicio a la aplicaci\u00f3n. Los bucles de reintento ahora est\u00e1n limitados (200 intentos para RDSEED y 20 para RDRAND, el doble de las l\u00edneas base dadas en la gu\u00eda de implementaci\u00f3n de software del Generador de N\u00fameros Aleatorios Digitales de Intel), haciendo pausas entre intentos y, al agotarse, limpiando cualquier b\u00fafer parcialmente escrito y lanzando una excepci\u00f3n en lugar de seguir en bucle. La limpieza se realiza mediante un memzero no eludible, que utiliza un puntero vol\u00e1til y una barrera de memoria de ensamblador para que un compilador no pueda optimizar el borrado como un almacenamiento muerto. Bouncy Castle para Java (bcprov) no se ve afectado, ya que no tiene una fuente de entrop\u00eda nativa; las series FIPS 1.0.X y 2.0.X no se ven afectadas."
}
],
"id": "CVE-2026-8798",
"lastModified": "2026-10-24T13:10:00.147",
"metrics": {
"cvssMetricV40": [
{
"cvssData": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"availabilityRequirement": "NOT_DEFINED",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"confidentialityRequirement": "NOT_DEFINED",
"exploitMaturity": "NOT_DEFINED",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"modifiedAttackRequirements": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"modifiedPrivilegesRequired": "NOT_DEFINED",
"modifiedSubAvailabilityImpact": "NOT_DEFINED",
"modifiedSubConfidentialityImpact": "NOT_DEFINED",
"modifiedSubIntegrityImpact": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedVulnAvailabilityImpact": "NOT_DEFINED",
"modifiedVulnConfidentialityImpact": "NOT_DEFINED",
"modifiedVulnIntegrityImpact": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "AMBER",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Amber",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "91579145-5d7b-4cc5-b925-a0262ff19630",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-8798",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-10T16:25:32.762419Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-08-08T01:16:31.393",
"references": [
{
"source": "91579145-5d7b-4cc5-b925-a0262ff19630",
"url": "https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%908798"
}
],
"sourceIdentifier": "91579145-5d7b-4cc5-b925-a0262ff19630",
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-835"
}
],
"source": "91579145-5d7b-4cc5-b925-a0262ff19630",
"type": "Secondary"
}
]
}
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-8798",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-08-10T16:25:32.762419Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-08-10T16:25:39.744Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"collectionURL": "https://www.bouncycastle.org/download/bouncy-castle-java-fips/",
"defaultStatus": "unaffected",
"packageName": "bc-fips",
"packageURL": "pkg:maven/org.bouncycastle/bc-fips",
"platforms": [
"x86",
"x86-64"
],
"product": "BC-FJA",
"programFiles": [
"rand_jni.c",
"NativeEntropySource"
],
"vendor": "Legion of the Bouncy Castle Inc.",
"versions": [
{
"lessThan": "2.1.3",
"status": "affected",
"version": "2.1.0",
"versionType": "maven"
}
]
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "\u003cp\u003eIn Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.1.3, the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound. RDSEED and RDRAND report failure through their carry flag, and the JNI seeding routine spun re-issuing the instruction for as long as that flag stayed clear, so a persistent failure of the on-chip entropy source - whether from a hardware fault, from the underlying DRBG being exhausted by contention across many cores, or from a hypervisor that does not provide the instruction - left the calling thread looping indefinitely inside the JNI call, where it could be neither interrupted nor timed out. Any operation drawing from the native entropy source could therefore hang, denying service to the application. The retry loops are now bounded (200 attempts for RDSEED and 20 for RDRAND, twice the baselines given in Intel\u0027s Digital Random Number Generator software implementation guide), pausing between attempts and, on exhaustion, clearing any partially written buffer and throwing rather than continuing to spin. The clear is performed by an un-elidable memzero, which uses a volatile pointer and an assembly memory barrier so that a compiler cannot optimise the erase away as a dead store. Bouncy Castle for Java (bcprov) is not affected, as it has no native entropy source; the 1.0.X and 2.0.X FIPS series are not affected.\u003c/p\u003e"
}
],
"value": "In Bouncy Castle for Java FIPS (BC-FJA) before bc-fips 2.1.3, the native entropy source used on Intel platforms retried the CPU entropy instructions without any bound. RDSEED and RDRAND report failure through their carry flag, and the JNI seeding routine spun re-issuing the instruction for as long as that flag stayed clear, so a persistent failure of the on-chip entropy source - whether from a hardware fault, from the underlying DRBG being exhausted by contention across many cores, or from a hypervisor that does not provide the instruction - left the calling thread looping indefinitely inside the JNI call, where it could be neither interrupted nor timed out. Any operation drawing from the native entropy source could therefore hang, denying service to the application. The retry loops are now bounded (200 attempts for RDSEED and 20 for RDRAND, twice the baselines given in Intel\u0027s Digital Random Number Generator software implementation guide), pausing between attempts and, on exhaustion, clearing any partially written buffer and throwing rather than continuing to spin. The clear is performed by an un-elidable memzero, which uses a volatile pointer and an assembly memory barrier so that a compiler cannot optimise the erase away as a dead store. Bouncy Castle for Java (bcprov) is not affected, as it has no native entropy source; the 1.0.X and 2.0.X FIPS series are not affected."
}
],
"metrics": [
{
"cvssV4_0": {
"Automatable": "NOT_DEFINED",
"Recovery": "NOT_DEFINED",
"Safety": "NOT_DEFINED",
"attackComplexity": "LOW",
"attackRequirements": "NONE",
"attackVector": "NETWORK",
"baseScore": 8.7,
"baseSeverity": "HIGH",
"exploitMaturity": "NOT_DEFINED",
"privilegesRequired": "NONE",
"providerUrgency": "AMBER",
"subAvailabilityImpact": "NONE",
"subConfidentialityImpact": "NONE",
"subIntegrityImpact": "NONE",
"userInteraction": "NONE",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/U:Amber",
"version": "4.0",
"vulnAvailabilityImpact": "HIGH",
"vulnConfidentialityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-835",
"description": "CWE-835 Loop with Unreachable Exit Condition (\u0027Infinite Loop\u0027)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-08T00:50:56.956Z",
"orgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
"shortName": "bcorg"
},
"references": [
{
"tags": [
"vendor-advisory"
],
"url": "https://github.com/bcgit/bc-java/wiki/CVE%E2%80%902026%E2%80%908798"
}
],
"source": {
"discovery": "INTERNAL"
},
"title": "Native entropy source retries the CPU entropy instructions without limit",
"x_generator": {
"engine": "bc release-notes template"
}
}
},
"cveMetadata": {
"assignerOrgId": "91579145-5d7b-4cc5-b925-a0262ff19630",
"assignerShortName": "bcorg",
"cveId": "CVE-2026-8798",
"datePublished": "2026-08-08T00:50:56.956Z",
"dateReserved": "2026-05-18T01:17:23.058Z",
"dateUpdated": "2026-08-10T18:23:28.568Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
Loading…
Loading…
Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.
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.
Vulnerability timeline
Sightings and recorded dates, grouped by day · UTC
Loading timeline…
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.