CVE-2026-6924 (GCVE-0-2026-6924)
Vulnerability from cvelistv5 – Published: 2026-07-23 21:05 – Updated: 2026-07-24 13:40
VLAI
EPSS
VEX
Title
Weak entropy initialization in Silicon Labs Matter SiWx917 TinyCrypt path
Summary
A bug in the entropy initialization for SiWx917 causes the DRBG to use a predictable seed. As such, all random numbers generated in the Matter code use the same stream of numbers. This vulnerability was discovered after the impacted repository was already deprecated.
Severity
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-07-24 13:40 UTC
CWE
- CWE-336 - Same Seed in Pseudo-Random Number Generator (PRNG)
Assigner
References
2 references
| URL | Tags |
|---|---|
| https://siliconlabs.lightning.force.com/sfc/servl… | vendor-advisorypermissions-required |
| https://github.com/SiliconLabs/matter/tree/releas… | patch |
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Silicon Labs | Silicon Labs Matter Github |
Affected:
0
(semver)
|
guessed |
{
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-6924",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-24T13:40:22.863000Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-24T13:40:36.220Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Silicon Labs Matter Github",
"repo": "https://github.com/SiliconLabs/simplicity_sdk",
"vendor": "Silicon Labs",
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "reporter",
"value": "Junming C. (@Chapoly1305) and Prof. Qiang Zeng of George Mason University"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "A bug in the entropy initialization for SiWx917 causes the DRBG to use a predictable seed. As such, all random numbers generated in the Matter code use the same stream of numbers. This vulnerability was discovered after the impacted repository was already deprecated."
}
],
"value": "A bug in the entropy initialization for SiWx917 causes the DRBG to use a predictable seed. As such, all random numbers generated in the Matter code use the same stream of numbers. This vulnerability was discovered after the impacted repository was already deprecated."
}
],
"impacts": [
{
"capecId": "CAPEC-97",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-97: Cryptanalysis"
}
]
}
],
"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": "NOT_DEFINED",
"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:H/VI:N/VA:N/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-336",
"description": "CWE-336: Same Seed in Pseudo-Random Number Generator (PRNG)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-23T21:05:22.113Z",
"orgId": "030b2754-1501-44a4-bef8-48be86a33bf4",
"shortName": "Silabs"
},
"references": [
{
"tags": [
"vendor-advisory",
"permissions-required"
],
"url": "https://siliconlabs.lightning.force.com/sfc/servlet.shepherd/document/download/a45Vm0000009SzZIAU?operationContext=S1"
},
{
"tags": [
"patch"
],
"url": "https://github.com/SiliconLabs/matter/tree/release_2.3.1-1.3"
}
],
"source": {
"discovery": "INTERNAL"
},
"title": "Weak entropy initialization in Silicon Labs Matter SiWx917 TinyCrypt path",
"x_generator": {
"engine": "Vulnogram 1.0.4"
}
}
},
"cveMetadata": {
"assignerOrgId": "030b2754-1501-44a4-bef8-48be86a33bf4",
"assignerShortName": "Silabs",
"cveId": "CVE-2026-6924",
"datePublished": "2026-07-23T21:05:22.113Z",
"dateReserved": "2026-04-23T17:11:02.116Z",
"dateUpdated": "2026-07-24T13:40:36.220Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2026-6924",
"date": "2026-11-01",
"epss": "0.00445",
"percentile": "0.38693"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Silicon Labs Matter Github",
"repo": "https://github.com/SiliconLabs/simplicity_sdk",
"vendor": "Silicon Labs",
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"source": "product-security@silabs.com"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "A bug in the entropy initialization for SiWx917 causes the DRBG to use a predictable seed. As such, all random numbers generated in the Matter code use the same stream of numbers. This vulnerability was discovered after the impacted repository was already deprecated."
},
{
"lang": "es",
"value": "Un error en la inicializaci\u00f3n de la entrop\u00eda para SiWx917 provoca que el DRBG utilice una semilla predecible. Como tal, todos los n\u00fameros aleatorios generados en el c\u00f3digo de Matter utilizan la misma secuencia de n\u00fameros. Esta vulnerabilidad fue descubierta despu\u00e9s de que el repositorio afectado ya hab\u00eda sido desaprobado."
}
],
"id": "CVE-2026-6924",
"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": "NOT_DEFINED",
"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:H/VI:N/VA:N/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:X",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"source": "product-security@silabs.com",
"type": "Secondary"
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-6924",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-24T13:40:22.863000Z",
"version": "2.0.3"
}
}
]
},
"published": "2026-07-23T21:17:05.447",
"references": [
{
"source": "product-security@silabs.com",
"url": "https://github.com/SiliconLabs/matter/tree/release_2.3.1-1.3"
},
{
"source": "product-security@silabs.com",
"url": "https://siliconlabs.lightning.force.com/sfc/servlet.shepherd/document/download/a45Vm0000009SzZIAU?operationContext=S1"
}
],
"sourceIdentifier": "product-security@silabs.com",
"vulnStatus": "Awaiting Analysis",
"weaknesses": [
{
"description": [
{
"lang": "en",
"value": "CWE-336"
}
],
"source": "product-security@silabs.com",
"type": "Secondary"
}
]
}
},
"vulnrichment": {
"containers": {
"adp": [
{
"metrics": [
{
"other": {
"content": {
"id": "CVE-2026-6924",
"options": [
{
"Exploitation": "none"
},
{
"Automatable": "yes"
},
{
"Technical Impact": "partial"
}
],
"role": "CISA Coordinator",
"timestamp": "2026-07-24T13:40:22.863000Z",
"version": "2.0.3"
},
"type": "ssvc"
}
}
],
"providerMetadata": {
"dateUpdated": "2026-07-24T13:40:29.288Z",
"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"shortName": "CISA-ADP"
},
"title": "CISA ADP Vulnrichment"
}
],
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Silicon Labs Matter Github",
"repo": "https://github.com/SiliconLabs/simplicity_sdk",
"vendor": "Silicon Labs",
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver"
}
]
}
],
"credits": [
{
"lang": "en",
"type": "reporter",
"value": "Junming C. (@Chapoly1305) and Prof. Qiang Zeng of George Mason University"
}
],
"descriptions": [
{
"lang": "en",
"supportingMedia": [
{
"base64": false,
"type": "text/html",
"value": "A bug in the entropy initialization for SiWx917 causes the DRBG to use a predictable seed. As such, all random numbers generated in the Matter code use the same stream of numbers. This vulnerability was discovered after the impacted repository was already deprecated."
}
],
"value": "A bug in the entropy initialization for SiWx917 causes the DRBG to use a predictable seed. As such, all random numbers generated in the Matter code use the same stream of numbers. This vulnerability was discovered after the impacted repository was already deprecated."
}
],
"impacts": [
{
"capecId": "CAPEC-97",
"descriptions": [
{
"lang": "en",
"value": "CAPEC-97: Cryptanalysis"
}
]
}
],
"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": "NOT_DEFINED",
"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:H/VI:N/VA:N/SC:N/SI:N/SA:N",
"version": "4.0",
"vulnAvailabilityImpact": "NONE",
"vulnConfidentialityImpact": "HIGH",
"vulnIntegrityImpact": "NONE",
"vulnerabilityResponseEffort": "NOT_DEFINED"
},
"format": "CVSS",
"scenarios": [
{
"lang": "en",
"value": "GENERAL"
}
]
}
],
"problemTypes": [
{
"descriptions": [
{
"cweId": "CWE-336",
"description": "CWE-336: Same Seed in Pseudo-Random Number Generator (PRNG)",
"lang": "en",
"type": "CWE"
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-07-23T21:05:22.113Z",
"orgId": "030b2754-1501-44a4-bef8-48be86a33bf4",
"shortName": "Silabs"
},
"references": [
{
"tags": [
"vendor-advisory",
"permissions-required"
],
"url": "https://siliconlabs.lightning.force.com/sfc/servlet.shepherd/document/download/a45Vm0000009SzZIAU?operationContext=S1"
},
{
"tags": [
"patch"
],
"url": "https://github.com/SiliconLabs/matter/tree/release_2.3.1-1.3"
}
],
"source": {
"discovery": "INTERNAL"
},
"title": "Weak entropy initialization in Silicon Labs Matter SiWx917 TinyCrypt path",
"x_generator": {
"engine": "Vulnogram 1.0.4"
}
}
},
"cveMetadata": {
"assignerOrgId": "030b2754-1501-44a4-bef8-48be86a33bf4",
"assignerShortName": "Silabs",
"cveId": "CVE-2026-6924",
"datePublished": "2026-07-23T21:05:22.113Z",
"dateReserved": "2026-04-23T17:11:02.116Z",
"dateUpdated": "2026-07-24T13:40:36.220Z",
"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
How durations are calculated
Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.
Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.
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.