CVE-2026-5773
Status: ModifiedHigh (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
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- Base score: 7.5
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 0.66%
- Percentile among all scored CVEs: 50
- Score date: 10/4/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
🎯 ATT&CK techniques
How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.
- Exploitation
T1190Exploit Public-Facing Applicationinitial access75 % - Primary impact
T1005Data from Local Systemcollection70 % - Secondary impact
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.
Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.
🛡️ ATT&CK mitigations that cover these techniques
Affected technologies (1)
CWEs
- CWE-488
- CWE-918
References
Raw JSON (NVD)
Show
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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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