CVE-2026-5773

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

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

References

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