# CVE-2026-44312: ruby-css-parser: css_parser is a Ruby CSS parser

CVE-2026-44312 is fixed in ruby-css-parser on 1 platform, first by DEBIAN-CVE-2026-44312, released May 15, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-44312
- Priority: Routine
- CVSS: 5.8 (medium)
- EPSS: 0.0015
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 14, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | ruby-css-parser Debian 12.15 (bookworm) | 1.6.0-2+deb12u1 | [DEBIAN-CVE-2026-44312](https://patchblox.com/security/data/fix/linux/debian-cve-2026-44312.md) | May 15, 2026 |
| Linux | ruby-css-parser Debian 13.5 (trixie) | 1.19.0-1+deb13u1 | [DEBIAN-CVE-2026-44312](https://patchblox.com/security/data/fix/linux/debian-cve-2026-44312.md) | May 15, 2026 |
| Linux | ruby-css-parser Debian 14 | 2.1.0-1 | [DEBIAN-CVE-2026-44312](https://patchblox.com/security/data/fix/linux/debian-cve-2026-44312.md) | May 15, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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