CVE-2026-61500

Rejetto HFS 3.0.0 through 3.2.0 derives its session-cookie signing key from the non-cryptographic Math.random() generator and discloses outputs of the same generator to unauthenticated clients during login. A remote attacker can collect a small number of login responses, reconstruct the generator's state, recover the signing key, and forge a valid administrator session cookie, leading to full administrative access and remote code execution via the server_code configuration feature.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/rejetto/hfs/releases/tag/v3.2.1
https://www.vulncheck.com/advisories/rejetto-hfs-session-forgery-via-predictable-signing-key

Configurations

No configuration.

History

24 Oct 2026, 22:10

Type	Values Removed	Values Added
Summary		(es) Rejetto HFS 3.0.0 hasta 3.2.0 deriva su clave de firma de la cookie de sesión del generador no criptográfico Math.random() y revela las salidas del mismo generador a clientes no autenticados durante el inicio de sesión. Un atacante remoto puede recopilar un pequeño número de respuestas de inicio de sesión, reconstruir el estado del generador, recuperar la clave de firma y falsificar una cookie de sesión de administrador válida, lo que lleva a acceso administrativo completo y ejecución remota de código a través de la característica de configuración server_code.

Information

Published : 2026-07-13 18:16

Updated : 2026-10-24 22:10

NVD link : CVE-2026-61500

Mitre link : CVE-2026-61500

CVE.ORG link : CVE-2026-61500

JSON object : View

Products Affected

No product.

CWE

CWE-338

Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

{"id": "CVE-2026-61500", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-61500", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-07-15T14:14:22.207797Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 3.9}], "cvssMetricV40": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/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:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "disclosure@vulncheck.com", "affectedData": [{"repo": "https://github.com/rejetto/hfs", "vendor": "rejetto", "product": "hfs", "versions": [{"status": "affected", "version": "3.0.0", "lessThan": "3.2.1", "versionType": "semver"}], "packageURL": "pkg:github/rejetto/hfs", "defaultStatus": "affected"}]}], "published": "2026-07-13T18:16:29.903", "references": [{"url": "https://github.com/rejetto/hfs/releases/tag/v3.2.1", "source": "disclosure@vulncheck.com"}, {"url": "https://www.vulncheck.com/advisories/rejetto-hfs-session-forgery-via-predictable-signing-key", "source": "disclosure@vulncheck.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "description": [{"lang": "en", "value": "CWE-338"}]}], "descriptions": [{"lang": "en", "value": "Rejetto HFS 3.0.0 through 3.2.0 derives its session-cookie signing key from the non-cryptographic Math.random() generator and discloses outputs of the same generator to unauthenticated clients during login. A remote attacker can collect a small number of login responses, reconstruct the generator's state, recover the signing key, and forge a valid administrator session cookie, leading to full administrative access and remote code execution via the server_code configuration feature."}, {"lang": "es", "value": "Rejetto HFS 3.0.0 hasta 3.2.0 deriva su clave de firma de la cookie de sesi\u00f3n del generador no criptogr\u00e1fico Math.random() y revela las salidas del mismo generador a clientes no autenticados durante el inicio de sesi\u00f3n. Un atacante remoto puede recopilar un peque\u00f1o n\u00famero de respuestas de inicio de sesi\u00f3n, reconstruir el estado del generador, recuperar la clave de firma y falsificar una cookie de sesi\u00f3n de administrador v\u00e1lida, lo que lleva a acceso administrativo completo y ejecuci\u00f3n remota de c\u00f3digo a trav\u00e9s de la caracter\u00edstica de configuraci\u00f3n server_code."}], "lastModified": "2026-10-24T22:10:00.210", "sourceIdentifier": "disclosure@vulncheck.com"}