CVE-2026-73291
Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby. Prior to version 3.4.0, Seerr's ImageProxy in server/lib/imageproxy.ts uses the upstream ETag and Content-Type response headers to build a cache filename for the unauthenticated GET /avatarproxy/:jellyfinUserId route, allowing a malicious or compromised Jellyfin or Emby server, or a man-in-the-middle attacker on a plaintext media-server connection, to supply traversal sequences that path.join and fs.writeFile normalize outside the cache directory, overwrite /app/dist/index.js or other files, and execute code as the node user after a container restart. This issue is fixed in version 3.4.0.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H
- Puntuación base: 7.1
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.39%
- Percentil entre todas las CVEs puntuadas: 31
- Fecha de la puntuación: 6/10/2026
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
T1210Exploitation of Remote Serviceslateral movement85 % - Impacto principal
T1059Command and Scripting Interpreterexecution80 % - Impacto secundario
T1005Data from Local Systemcollection70 % - Impacto secundario
T1565.001Stored Data Manipulationimpact75 %
Vulnerabilidad en servidor remoto (Jellyfin/Emby) accesible sin autenticación previa; permite path traversal (CWE-22) y ejecución de código (CWE-94) mediante sobrescritura de archivos via headers HTTP maliciosos en conexión de red adyacente.
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 (4)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
CWE
- CWE-22, CWE-94
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-73291",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2026-73291",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2026-08-13T16:22:56.578886Z"
}
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.1,
"attackVector": "ADJACENT_NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "NONE",
"attackComplexity": "HIGH",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 5.5,
"exploitabilityScore": 1.6
}
]
},
"affected": [
{
"source": "security-advisories@github.com",
"affectedData": [
{
"vendor": "seerr-team",
"product": "seerr",
"versions": [
{
"status": "affected",
"version": "< 3.4.0"
}
]
}
]
}
],
"published": "2026-08-12T15:18:33.020",
"references": [
{
"url": "https://github.com/seerr-team/seerr/commit/f484791105bd81bd5404e01410431ee6fe5769c2",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/seerr-team/seerr/releases/tag/v3.4.0",
"source": "security-advisories@github.com"
},
{
"url": "https://github.com/seerr-team/seerr/security/advisories/GHSA-mc6w-69r3-62h8",
"source": "security-advisories@github.com"
}
],
"vulnStatus": "Deferred",
"weaknesses": [
{
"type": "Secondary",
"source": "security-advisories@github.com",
"description": [
{
"lang": "en",
"value": "CWE-22"
},
{
"lang": "en",
"value": "CWE-94"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Seerr is an open-source media request and discovery manager for Jellyfin, Plex, and Emby. Prior to version 3.4.0, Seerr's ImageProxy in server/lib/imageproxy.ts uses the upstream ETag and Content-Type response headers to build a cache filename for the unauthenticated GET /avatarproxy/:jellyfinUserId route, allowing a malicious or compromised Jellyfin or Emby server, or a man-in-the-middle attacker on a plaintext media-server connection, to supply traversal sequences that path.join and fs.writeFile normalize outside the cache directory, overwrite /app/dist/index.js or other files, and execute code as the node user after a container restart. This issue is fixed in version 3.4.0."
}
],
"lastModified": "2026-09-18T20:09:01.757",
"sourceIdentifier": "security-advisories@github.com"
}