GitLab CE/EE: Authenticated DoS via Nested Markdown (pre18.4.4)
CVE-2025-12983 Published on November 15, 2025
Memory Allocation with Excessive Size Value in GitLab
GitLab has remediated an issue in GitLab CE/EE affecting all versions from 16.9 before 18.3.6, 18.4 before 18.4.4, and 18.5 before 18.5.2 that could have allowed an authenticated attacker to cause a denial of service condition by submitting specially crafted markdown content with nested formatting patterns.
Vulnerability Analysis
CVE-2025-12983 can be exploited with network access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.
Weakness Type
What is a Stack Exhaustion Vulnerability?
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
CVE-2025-12983 has been classified to as a Stack Exhaustion vulnerability or weakness.
Products Associated with CVE-2025-12983
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Affected Versions
GitLab:- Version 16.9 and below 18.3.6 is affected.
- Version 18.4 and below 18.4.4 is affected.
- Version 18.5 and below 18.5.2 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.