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Vulnerability record · CVE-2026-5773 · published 13 May 2026

CVE-2026-5773: Haxx curl server-side request forgery (ssrf) vulnerability

Haxx · Curl

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.

7.5 CVSS 3.1 High EPSS 0.66% · top 50.6% CWE-488 · CWE-488CWE-918 · Server-side request forgery (SSRF)
7.5CVSS 3.1 base score
0.66%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
5References, 2 tagged exploit
15 Sep 2026Last modified by NVD

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://curl.se/docs/CVE-2026-5773.html PatchVendor Advisory
https://curl.se/docs/CVE-2026-5773.json Vendor Advisory
https://hackerone.com/reports/3650689 ExploitIssue TrackingThird Party Advisory
http://www.openwall.com/lists/oss-security/2026/04/29/9 Mailing ListPatchThird Party Advisory
https://hackerone.com/reports/3650689 ExploitIssue TrackingThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-5773), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.