curl: CURLOPT_PROXY_CRLFILE / CURLOPT_PROXY_ISSUERCERT / CURLOPT_PROXY_ISSUERCERT_BLOB silently ignored on backends that don't support them

🗓️ 06 May 2026 21:23:18Reported by bagderType

hackerone

hackerone🔗 hackerone.com👁 7 Views

Curl ignores proxy CRLFILE and ISSUERCERT options on unsupported backends, allowing revoked proxy certificates.

Reporter	Title	Published	Views	Family All 189
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Tenable Nessus	Azure Linux 3.0 Security Update: cmake / curl (CVE-2024-2466)	10 Feb 202500:00	–	nessus
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05 Jun 2026 07:03Current

6.5Medium risk

Vulners AI Score6.5

CVSS 3.16.5

EPSS0.00149

SSVC

curl proxy crlfile issuer cert issuer cert blob unsupported backends wolfssl mbedtls schannel rustls openssl low severity proxy issue certificate revocation