CVE-2026-5773

Published: May 1, 2026Last modified: May 5, 2026

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.

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References

• http://www.openwall.com/lists/oss-security/2026/04/29/9
• https://curl.se/docs/CVE-2026-5773.html
• https://curl.se/docs/CVE-2026-5773.json
• https://hackerone.com/reports/3650689