CURL-CVE-2026-9546

vendorUSosv

sending old referer

view advisory published 2026-06-24Licence: per source

A vulnerability in libcurl caused the HTTP `Referer:` header to persist even when explicitly cleared. While the documentation states that passing NULL to `CURLOPT_REFERER` suppresses the header, the option failed to clear the internal state. As a result, the previous referrer string was erroneously reused and sent in subsequent requests, potentially leaking sensitive information to unintended servers.

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describes (1)

Related CVEs.

IDseverity exploitable
CVE-2026-9546US——
A vulnerability in libcurl caused the HTTP `Referer:` header to persist even when explicitly cleared. While the documentation states that passing NULL to `CURLOPT_REFERER` suppress…
scry

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