Medium severity5.8GHSA Advisory· Published May 14, 2026· Updated May 15, 2026
CVE-2026-44312
CVE-2026-44312
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
css_parserRubyGems | >= 2.0.0, < 2.1.0 | 2.1.0 |
css_parserRubyGems | < 1.22.0 | 1.22.0 |
Affected products
3- Range: < 2.1.0
- osv-coords2 versions
< 18.7.6-r3+ 1 more
- (no CPE)range: < 18.7.6-r3
- (no CPE)range: >= 2.0.0, < 2.1.0
Patches
Vulnerability mechanics
References
7- github.com/advisories/GHSA-ff6c-w6qf-7xqcghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-44312ghsaADVISORY
- github.com/premailer/css_parser/commit/35e689c904225add78e0c488cf04bad052666449nvdWEB
- github.com/premailer/css_parser/commit/e0c95d5abe91b237becb90ff316531a6547ada18nvdWEB
- github.com/premailer/css_parser/issues/185nvdWEB
- github.com/premailer/css_parser/security/advisories/GHSA-ff6c-w6qf-7xqcnvdWEB
- github.com/rubysec/ruby-advisory-db/blob/master/gems/css_parser/CVE-2026-44312.ymlghsaWEB
News mentions
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