CVE-2026-44312
css_parser allows to MITM included https css urls
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.
INFO
Published Date :
May 14, 2026, 5:16 p.m.
Last Modified :
May 14, 2026, 6:13 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-44312
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update to CSS Parser gem version 2.1.0 or later.
- Update to CSS Parser gem version 1.22.0 or later.
- Ensure OpenSSL::SSL::VERIFY_NONE is not used for HTTPS connections.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-44312.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-44312 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-44312
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-44312 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-44312 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
May. 14, 2026
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N Added CWE CWE-295 Added CWE CWE-829 Added Reference https://github.com/premailer/css_parser/commit/35e689c904225add78e0c488cf04bad052666449 Added Reference https://github.com/premailer/css_parser/commit/e0c95d5abe91b237becb90ff316531a6547ada18 Added Reference https://github.com/premailer/css_parser/issues/185 Added Reference https://github.com/premailer/css_parser/security/advisories/GHSA-ff6c-w6qf-7xqc