CVE-2026-44312
Medium
Description
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.
SeverityMedium
CVSS5.8
Exploit probability—
ProductPremailer Css Parser
PublishedMay 14, 2026
First seenMay 14, 2026
Weakness typeCWE-829CWE-829CWE-295CWE-295
How to fix
Sources list no fixed version or patch link for this vulnerability.
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| premailer css_parser | >= 2.0.0, < 2.1.0, < 1.22.0 | — |
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