VulnerabilityModified

CVE-2026-5773

HIGH 7.5EPSS 0.62%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.62%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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: 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS: 0.62% probability · 49th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-488, CWE-918
Affected: haxx/curl
Source: 2499f714-1537-4658-8207-48ae4bb9eae9

EPSS trend

EPSS 0.6% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

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

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.