CVE-2026-44312

Summary

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 Software

VendorProductVersion RangeStatus
premailercss_parser>= 2.0.0, < 2.1.0affected
premailercss_parser< 1.22.0affected

Weaknesses

  • CWE-829: CWE-829: Inclusion of Functionality from Untrusted Control Sphere
  • CWE-295: CWE-295: Improper Certificate Validation

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

References