The vulnerability originates from improper cache key construction in GitLab, allowing an authenticated user to inject extraneous untrusted data into cache keys that are presumed trusted. This flaw permits cache poisoning, where a malicious actor can serve modified cached page content to other users. The weakness is a classic example of CWE‑349, which permits malicious modification of data integrity for affected repositories.

Affected products include GitLab Community Edition and Enterprise Edition versions from 16.2 up to, but not including, 19.2.8, 19.3 before 19.3.5, and 19.4 before 19.4.2. All deployments using those version ranges are vulnerable when configured to allow authenticated cache access. The version constraints are listed by the CNA, and the provided patch versions begin at 19.2.8, 19.3.5, and 19.4.2.

The CVSS score of 4.6 indicates a moderate severity, and no EPSS score is available, so the likelihood of exploitation is uncertain. The vulnerability is not currently listed in the CISA KEV catalog, suggesting no known widespread exploitation. However, because the flaw allows an authenticated user to modify content served to others, organizations should address the issue promptly by applying the available patch and reviewing their caching configuration.