In CSS Validator less than or equal to commit 54d68a1, there is a cross-site scripting vulnerability in handling URIs. A user would have to click on a specifically crafted validator link to trigger it. This has been patched in commit e5c09a9.
This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 4.6, indicating it can be exploited remotely over the network with relatively low complexity though user interaction is required requiring only low-level privileges . The vulnerability impacts limited data confidentiality, limited integrity, for affected systems. Impacting 1 product from w3c organizations running these solutions should prioritize assessment and patching.
Reported in 2020, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2020-06-22T16:15:11.963
2026-06-17T03:19:31.040
Modified
CVSSv3.1: 4.6 (MEDIUM)
AV:N/AC:M/Au:S/C:N/I:P/A:N
6.8
2.9
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | w3c | css_validator | ≤ 2020-01-19 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For w3c's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.