Improper Certificate Validation Affecting curl package, versions [8.11.0,8.21.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-UNMANAGED-CURL-17808138
- published3 Jul 2026
- disclosed3 Jul 2026
- creditUnknown
Introduced: 3 Jul 2026
CVE-2026-9545 (opens in a new tab)How to fix?
Upgrade curl to version 8.21.0 or higher.
Overview
curl is a command line tool and library for transferring data with URL syntax, supporting DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET and TFTP. libcurl offers a myriad of powerful features.
Affected versions of this package are vulnerable to Improper Certificate Validation when the CURLOPT_SSL_SESSIONID_CACHE is enabled and the CURLSSLOPT_EARLYDATA option is set in CURLOPT_SSL_OPTIONS. An attacker can intercept and obtain sensitive information by impersonating a server and exploiting the reuse of cached SSL sessions before certificate verification is enforced. This is only exploitable if early data is enabled and SSL session ID caching is not disabled.