CVE-2026-44312
css_parser allows to MITM included https css urls
MEDIUM 5.8EPSS 0.2%
css_parser is a Ruby CSS parser. Prior to 2.1.0 and 1.22.0, the CSS Parser gem does not validate HTTPS connections, allowing a Man-in-the-Middle (MITM) attacker to inject or modify CSS content when stylesheets are loaded via HTTPS. The connection is established with OpenSSL::SSL::VERIFY_NONE, meaning any HTTPS certificate—even entirely untrusted—will be accepted without validation. This vulnerability is fixed in 2.1.0 and 1.22.0.
- Affected
- premailer · css_parser
- CVSS v3.1 GITHUB
- 5.8 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N - EPSS
- 0.24% chance of exploitation in the next 30 days, 14th percentile
- Published
- 2026-05-14
- Updated
- 2026-05-15