GitLab Community Edition/Enterprise Edition up to 18.3.5/18.4.3/18.5.1 Markdown memory allocation

CVSS Meta Temp Score
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CTI Interest Score
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4.3$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as problematic, was found in GitLab Community Edition and Enterprise Edition up to 18.3.5/18.4.3/18.5.1. This impacts an unknown function of the component Markdown Handler. Executing a manipulation can lead to memory allocation. This vulnerability is tracked as CVE-2025-12983. The attack can be launched remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in GitLab Community Edition and Enterprise Edition up to 18.3.5/18.4.3/18.5.1 and classified as problematic. This vulnerability affects some unknown functionality of the component Markdown Handler. The manipulation with an unknown input leads to a memory allocation vulnerability. The CWE definition for the vulnerability is CWE-789. 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. As an impact it is known to affect availability. CVE summarizes:

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.

The advisory is shared for download at about.gitlab.com. This vulnerability was named CVE-2025-12983 since 11/10/2025. The exploitation appears to be difficult. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 298824 (GitLab 16.9 < 18.3.6 / 18.4 < 18.4.4 / 18.5 < 18.5.2 (CVE-2025-12983)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 18.3.6, 18.4.4 or 18.5.2 eliminates this vulnerability. The upgrade is hosted for download at about.gitlab.com.

The vulnerability is also documented in the databases at Tenable (298824), EUVD (EUVD-2025-197698) and CERT Bund (WID-SEC-2025-2587). Once again VulDB remains the best source for vulnerability data.

Affected

  • Open Source GitLab

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.3

VulDB Base Score: 3.1
VulDB Temp Score: 3.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 6.5
NVD Vector: 🔒

CNA Base Score: 3.5
CNA Vector (GitLab): 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Memory allocation
CWE: CWE-789 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298824
Nessus Name: GitLab 16.9 < 18.3.6 / 18.4 < 18.4.4 / 18.5 < 18.5.2 (CVE-2025-12983)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Community Edition/Enterprise Edition 18.3.6/18.4.4/18.5.2

Timelineinfo

11/10/2025 CVE reserved
11/15/2025 +5 days Advisory disclosed
11/15/2025 +0 days VulDB entry created
02/15/2026 +92 days VulDB entry last update

Sourcesinfo

Vendor: gitlab.com

Advisory: 296257
Status: Confirmed

CVE: CVE-2025-12983 (🔒)
GCVE (CVE): GCVE-0-2025-12983
GCVE (VulDB): GCVE-100-332572
EUVD: 🔒
CERT Bund: WID-SEC-2025-2587 - GitLab: Mehrere Schwachstellen

Entryinfo

Created: 11/15/2025 14:42
Updated: 02/15/2026 23:58
Changes: 11/15/2025 14:42 (67), 11/15/2025 19:02 (1), 11/16/2025 19:01 (7), 11/20/2025 07:19 (11), 02/15/2026 23:58 (2)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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