CVE-2026-5773
Estado: ModificadaAlta (7.5)—
libcurl might in some circumstances reuse the wrong connection for SMB(S) transfers.
libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead.
When reusing a connection a range of criteria must be met. Due to a logical error in the code, a network transfer operation that was requested by an application could wrongfully reuse an existing SMB connection to the same server that was using a different "share" than the new subsequent transfer should.
This could in unlucky situations lead to the download of the wrong file or the upload of a file to the wrong place. When this happens, the same credentials are used and the server name is the same.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Puntuación base: 7.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.66%
- Percentil entre todas las CVEs puntuadas: 50
- 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
T1190Exploit Public-Facing Applicationinitial access75 % - Impacto principal
T1005Data from Local Systemcollection70 % - Impacto secundario
T1565.001Stored Data Manipulationimpact65 %
AV:N, PR:N, UI:N indica explotación remota sin privilegios (T1190). La reutilización incorrecta de conexión SMB permite leer archivos ajenos (C:H) o escribir en ubicaciones erróneas, afectando confidencialidad e integridad de datos.
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)
CWE
- CWE-488
- CWE-918
Referencias
JSON original (NVD)
Mostrar
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"value": "libcurl might in some circumstances reuse the wrong connection for SMB(S)\ntransfers.\n\nlibcurl features a pool of recent connections so that subsequent requests can\nreuse an existing connection to avoid overhead.\n\nWhen reusing a connection a range of criteria must be met. Due to a logical\nerror in the code, a network transfer operation that was requested by an\napplication could wrongfully reuse an existing SMB connection to the same\nserver that was using a different \"share\" than the new subsequent transfer\nshould.\n\nThis could in unlucky situations lead to the download of the wrong file or the\nupload of a file to the wrong place. When this happens, the same credentials\nare used and the server name is the same."
}
],
"lastModified": "2026-09-15T07:16:28.820",
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