curl trailing dot domain super cookie
CVE-2026-8924 is a low-severity vulnerability in curl/libcurl cookie domain validation that allows a malicious HTTP server to set a "super cookie" by abusing trailing-dot hostnames and cookie domains. When curl accesses a URL whose hostname includes a trailing dot, such as example.co.uk., and the server responds with a cookie scoped to a public suffix domain with a trailing dot, such as Domain=co.uk., curl's Public Suffix List validation via libpsl can be bypassed. Without trailing dots, the same PSL check correctly identifies the domain as a public suffix and rejects the cookie. Due to this parsing/validation flaw, curl may store the cookie and later send it to unrelated domains under that suffix. The issue affects curl versions 7.46.0 through 8.20.0 and was fixed in 8.21.0.
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Exploits
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No public exploit code observed for this vulnerability.
Recent activity
6 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.
A curl/libcurl cookie handling vulnerability related to trailing-dot domains that can result in a super-cookie condition.
A curl cookie domain validation vulnerability where trailing dots could bypass Public Suffix List checks, allowing improper acceptance of cookies for public suffix domains.
A low-severity curl/libcurl vulnerability related to cookie handling for trailing-dot domains, enabling an overly broad 'super cookie' condition.
A low-severity curl cookie parsing vulnerability that allows malicious servers to set super cookies by abusing trailing-dot domains, bypassing Public Suffix List protections and causing cookies to be sent to unrelated third-party domains.
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Cross-references every affected SKU, including bundled OEM variants.
Community discussion across Reddit, Mastodon, and other social sources.