BIT-gitlab-2026-12635: Reliance on Reverse DNS Resolution for a Security-Critical Action in GitLab
GitLab CE/EE versions from 8.3 up to but not including 18.11.6, 19.0 up to 19.0.3, and 19.1 up to 19.1.1 contain a vulnerability where an authenticated maintainer user could make requests to internal network resources via mirror synchronization due to improper URL validation relying on reverse DNS resolution. This issue has been remediated in the specified fixed versions.
AI Analysis
Technical Summary
This vulnerability in GitLab CE/EE involves reliance on reverse DNS resolution for a security-critical action. Under certain conditions, an authenticated user with maintainer permissions could exploit improper URL validation during mirror synchronization to send requests to internal network resources. The issue affects versions from 8.3 before 18.11.6, 19.0 before 19.0.3, and 19.1 before 19.1.1. The vulnerability has been fixed in versions 18.11.6, 19.0.3, and 19.1.1 respectively.
Potential Impact
An authenticated user with maintainer role could leverage this vulnerability to make unauthorized requests to internal network resources through mirror synchronization. This could potentially expose internal services or data not intended to be accessible, but the overall severity is rated low.
Mitigation Recommendations
Upgrade GitLab CE/EE to versions 18.11.6 or later for the 8.3 series, 19.0.3 or later for the 19.0 series, and 19.1.1 or later for the 19.1 series to remediate this vulnerability. No additional mitigation steps are indicated.
BIT-gitlab-2026-12635: Reliance on Reverse DNS Resolution for a Security-Critical Action in GitLab
Description
GitLab CE/EE versions from 8.3 up to but not including 18.11.6, 19.0 up to 19.0.3, and 19.1 up to 19.1.1 contain a vulnerability where an authenticated maintainer user could make requests to internal network resources via mirror synchronization due to improper URL validation relying on reverse DNS resolution. This issue has been remediated in the specified fixed versions.
Affected software
pkg:bitnami/gitlabRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in GitLab CE/EE involves reliance on reverse DNS resolution for a security-critical action. Under certain conditions, an authenticated user with maintainer permissions could exploit improper URL validation during mirror synchronization to send requests to internal network resources. The issue affects versions from 8.3 before 18.11.6, 19.0 before 19.0.3, and 19.1 before 19.1.1. The vulnerability has been fixed in versions 18.11.6, 19.0.3, and 19.1.1 respectively.
Potential Impact
An authenticated user with maintainer role could leverage this vulnerability to make unauthorized requests to internal network resources through mirror synchronization. This could potentially expose internal services or data not intended to be accessible, but the overall severity is rated low.
Mitigation Recommendations
Upgrade GitLab CE/EE to versions 18.11.6 or later for the 8.3 series, 19.0.3 or later for the 19.0 series, and 19.1.1 or later for the 19.1 series to remediate this vulnerability. No additional mitigation steps are indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- BIT-gitlab-2026-12635
- Osv Schema Version
- 1.6.2
- Aliases
- ["CVE-2026-12635"]
- Ecosystems
- ["Bitnami"]
- Database Specific Severity
- Low
- Cvss Version
- null
Threat ID: 6a42ed7427e9c7971993934c
Added to database: 06/29/2026, 22:11:00 UTC
Last enriched: 06/29/2026, 22:39:21 UTC
Last updated: 06/29/2026, 23:56:44 UTC
Views: 4
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