CVE-2026-44312

css_parser allows to MITM included https css urls

MEDIUM
5.8
CVSS Score
Published: May 14, 2026 at 04:15 PM UTC
Updated: October 26, 2026 at 02:10 PM UTC
1 product affected across 1 vendorCss Parser

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Severity
MEDIUM5.8
Exploit prediction
EPSS 0.1%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.22.02.0.0 ≤ v < 2.1.02.0.0
Affected range stops below 1.22.0, so it looks safe — our inference, not a vendor statement
Affected range stops below 2.1.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

5.8MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-829CWE-295

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