CVE-2026-108741
Shepherd (shepherd-ai) versión 0.3.1 y anteriores contiene un bypass de protección contra falsificación de solicitudes del lado del servidor (SSRF) en el extra citation-checker porque el guard public_url valida una dirección resuelta pero fetch re-resuelve el nombre de host en el momento de la conexión. Los atacantes que plantan una URL de referencia manipulada en un documento verificado y controlan su DNS pueden rebindearla a direcciones internas, enviando solicitudes GET a servicios HTTP(S) internos y capturando respuestas en archivos de evidencia.
Traducción automática del texto original de NVD (en inglés).
CVSS
- Puntuación base
- 2.3
- Versión
- 4.0
- Vector
- CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/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
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días
- 0.18 %
- Percentil entre todas las CVEs puntuadas
- 7
- Fecha de la puntuación
- 20/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1189Drive-by Compromiseinitial access85 % - Impacto principal
T1090Proxycommand and control75 % - Impacto secundario
T1005Data from Local Systemcollection70 %
XSS/SSRF por rebinding DNS: atacante planta URL maliciosa en documento, controla DNS para redirigir a servicios internos. Captura respuestas en ficheros.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-367
Referencias
Mostrar las 5 referencias
- https://github.com/shepherd-agents/shepherd
- https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/fetch.py#L34-L55
- https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/network.py#L9-L17
- https://hackmd.io/@haind03/shepherd-citation-checker-dns-rebinding-ssrf
- https://www.vulncheck.com/advisories/shepherd-through-0.3.1-ssrf-via-dns-rebinding-in-citation-checker
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-108741",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-108741",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-10-13T15:49:34.302287Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 3.1,
"attackVector": "NETWORK",
"baseSeverity": "LOW",
"vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "REQUIRED",
"attackComplexity": "HIGH",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 1.4,
"exploitabilityScore": 1.6
}
],
"cvssMetricV40": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"cvssData": {
"Safety": "NOT_DEFINED",
"version": "4.0",
"Recovery": "NOT_DEFINED",
"baseScore": 2.3,
"Automatable": "NOT_DEFINED",
"attackVector": "NETWORK",
"baseSeverity": "LOW",
"valueDensity": "NOT_DEFINED",
"vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/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",
"exploitMaturity": "NOT_DEFINED",
"providerUrgency": "NOT_DEFINED",
"userInteraction": "PASSIVE",
"attackComplexity": "LOW",
"attackRequirements": "PRESENT",
"privilegesRequired": "NONE",
"subIntegrityImpact": "NONE",
"vulnIntegrityImpact": "NONE",
"integrityRequirement": "NOT_DEFINED",
"modifiedAttackVector": "NOT_DEFINED",
"subAvailabilityImpact": "NONE",
"vulnAvailabilityImpact": "NONE",
"availabilityRequirement": "NOT_DEFINED",
"modifiedUserInteraction": "NOT_DEFINED",
"modifiedAttackComplexity": "NOT_DEFINED",
"subConfidentialityImpact": "NONE",
"vulnConfidentialityImpact": "LOW",
"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/shepherd-agents/shepherd",
"vendor": "shepherd-agents",
"product": "Shepherd",
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver",
"lessThanOrEqual": "0.3.1"
}
],
"packageURL": "pkg:pypi/shepherd-ai",
"collectionURL": "https://pypi.org",
"defaultStatus": "unaffected"
}
]
}
],
"published": "2026-10-11T13:17:18.673",
"references": [
{
"url": "https://github.com/shepherd-agents/shepherd",
"source": "disclosure@vulncheck.com"
},
{
"url": "https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/fetch.py#L34-L55",
"source": "disclosure@vulncheck.com"
},
{
"url": "https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/network.py#L9-L17",
"source": "disclosure@vulncheck.com"
},
{
"url": "https://hackmd.io/@haind03/shepherd-citation-checker-dns-rebinding-ssrf",
"source": "disclosure@vulncheck.com"
},
{
"url": "https://www.vulncheck.com/advisories/shepherd-through-0.3.1-ssrf-via-dns-rebinding-in-citation-checker",
"source": "disclosure@vulncheck.com"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "disclosure@vulncheck.com",
"description": [
{
"lang": "en",
"value": "CWE-367"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Shepherd (shepherd-ai) through 0.3.1 contains a server-side request forgery guard bypass in the citation-checker extra because the public_url guard validates a resolved address but fetch re-resolves the hostname at connect time. Attackers who plant a crafted reference URL in a checked document and control its DNS can rebind it to internal addresses, sending GET requests to internal HTTP(S) services and capturing responses in evidence files."
}
],
"lastModified": "2026-10-16T19:18:44.867",
"sourceIdentifier": "disclosure@vulncheck.com"
}