CVE-2026-5773

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 v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://curl.se/docs/CVE-2026-5773.html	Patch Vendor Advisory
https://curl.se/docs/CVE-2026-5773.json	Vendor Advisory
https://hackerone.com/reports/3650689	Exploit Issue Tracking Third Party Advisory
http://www.openwall.com/lists/oss-security/2026/04/29/9	Mailing List Patch Third Party Advisory
https://hackerone.com/reports/3650689	Exploit Issue Tracking Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2026-05-13 13:01

Updated : 2026-09-15 07:16

NVD link : CVE-2026-5773

Mitre link : CVE-2026-5773

CVE.ORG link : CVE-2026-5773

JSON object : View

Products Affected

haxx

curl

CWE

CWE-488

Exposure of Data Element to Wrong Session

CWE-918

Server-Side Request Forgery (SSRF)

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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", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "ACA618E8-E657-401D-8884-FE82245671E2", "versionEndExcluding": "8.20.0", "versionStartIncluding": "7.40.0"}], "operator": "OR"}]}], "sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9"}