CVE-2026-9546
HIGH severity · CVSS 7.5 · Information disclosure
7.5CVSS HIGH
Summary
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.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactNone
Availability impactNone
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://curl.se/docs/CVE-2026-9546.html ↗