libcurl wrong connection reuse for different Negotiate services
CVE-2026-8458 is a low-severity libcurl vulnerability in the connection reuse logic for HTTP Negotiate-authenticated requests. Due to a logical error, libcurl can reuse an already authenticated connection for a new request targeting the same host and port with the same credentials even when the new request specifies a different Negotiate service name. The intended service name may be set with CURLOPT_SERVICE_NAME or CURLOPT_PROXY_SERVICE_NAME, but prior to the fix this service value was not properly included in the reuse decision. As a result, a live pooled connection authenticated for one service could be incorrectly reused for another service. The issue affects libcurl versions 7.43.0 through 8.20.0 inclusive and does not affect the curl command-line tool. The flaw was introduced by commit 97c272e5d173ad5f706 and fixed in curl 8.21.0 by making connection reuse account for the service name.
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A curl/libcurl vulnerability caused by incorrect connection reuse across different services.
A low-severity curl/libcurl vulnerability involving improper connection reuse across different services.
A low-severity libcurl vulnerability where a logical error can cause reuse of an existing Negotiate-authenticated connection for a different service on the same host, port, and credentials, potentially exposing data to the wrong session.
A curl vulnerability involving incorrect connection reuse across different services.
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Cross-references every affected SKU, including bundled OEM variants.
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