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.

References

https://github.com/premailer/css_parser/security/advisories/GHSA-ff6c-w6qf-7xqc

https://github.com/premailer/css_parser/issues/185

https://github.com/premailer/css_parser/commit/e0c95d5abe91b237becb90ff316531a6547ada18

https://github.com/premailer/css_parser/commit/35e689c904225add78e0c488cf04bad052666449

Details

Source: Mitre, NVD

Published: 2026-05-14

Updated: 2026-05-15

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 5.8

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Severity: Medium

EPSS

EPSS: 0.00016