CVE-2026-5773: high-severity vulnerability in curl
wrong reuse of SMB connection
Published · Updated
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.7%
exploitation probability
0.7%top 50% of all CVEs
observed exploitation
nono source reports it
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
curl · curlRelated CVEs — curl
In the same product, most dangerous first.