curl: CURLOPT_HSTS_CTRL disables shared HSTS without share guard — use-after-free and double-free

🗓️ 13 May 2026 21:50:15Reported by giant_anteaterType

Bug in curl HSTS control cleanup when sharing HSTS across handles leads to use-after-free and double-free.

Reporter	Title	Published	Views	Family All 185
FreeBSD	curl -- multiple vulnerabilities	20 Mar 202300:00	–	freebsd
FreeBSD	curl -- multiple vulnerabilities	31 Oct 201800:00	–	freebsd
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IBM Security Bulletins	Security Bulletin: IBM Dynamic System Analysis (DSA) Preboot is affected by vulnerabilities in cURL (CVE-2018-16840 CVE-2018-16842)	7 Dec 202322:45	–	ibm
IBM Security Bulletins	Security Bulletin: cURL as used by IBM QRadar WinCollect Agent contains multiple vulnerabilities	8 Jun 202321:14	–	ibm
IBM Security Bulletins	Security Bulletin: IBM InfoSphere Information Server is affected by multiple vulnerabilities in Progress DataDirect Connect for ODBC	26 Mar 202503:49	–	ibm
IBM Security Bulletins	Security Bulletin: The Community Edition of IBM ILOG CPLEX Optimization Studio is affected by a vulnerability in libcurl (CVE-2018-16840)	19 Nov 201815:50	–	ibm
IBM Security Bulletins	Security Bulletin: Vulnerabilities in cURL libcurl might affect IBM Spectrum Copy Data Management	15 Sep 202313:29	–	ibm
IBM Security Bulletins	Security Bulletin: IBM® Engineering Requirements Management DOORS/DWA vulnerabilities addressed in 9.7.2.8	18 Oct 202407:56	–	ibm

18 May 2026 13:25Current

6.7Medium risk

Vulners AI Score6.7

CVSS 27.5

CVSS 3.19.8

CVSS 34.3

EPSS0.0029

SSVC