Description
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.
Affected products
haxx: curl
References5
- curl.se/docs/CVE-2026-5773.html PatchVendor Advisory
- curl.se/docs/CVE-2026-5773.json Vendor Advisory
- www.openwall.com/lists/oss-security/2026/04/29/9 Mailing ListPatchThird Party Advisory
- hackerone.com/reports/3650689 ExploitIssue TrackingThird Party Advisory
- hackerone.com/reports/3650689 ExploitIssue TrackingThird Party Advisory
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N - EPSS — exploit probability
- 1% percentile: 50 · as of 14 November 2026
- CWE
- CWE-488CWE-918
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