CVE-2026-87861: critical vulnerability in curl
cross-origin reuse of a Negotiate connection
Published · Updated
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28Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 9.1epss 0.7%
When using ambient user credentials, an HTTP request directed to one origin
may be dispatched over a connection previously authenticated via Negotiate for
a different origin, leaving the request's intended credentials unused.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Affected products
curl · curlRelated CVEs — curl
In the same product, most dangerous first.