CVE-2025-12653 | Authentication Bypass by Spoofing in GitLab

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.3 before 18.4.5, 18.5 before 18.5.3, and 18.6 before 18.6.1 that under specific conditions could have allowed an unauthenticated user to join arbitrary organizations by changing headers on some requests.

Published: 2025-11-26 Last update: 2025-12-10 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-12653 is rated Low Risk (31.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-12653

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-25 0.04% 0.05% +0.01%
2 2026-04-24 0.05% 0.04% -0.01%
3 2026-02-02 — 0.05% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-12653

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 2.5 [email protected]

Weakness enumeration for CVE-2025-12653

OS Trackers for CVE-2025-12653

vendor priority summary link
debian unimportant CVE-2025-12653 unimportant priority: Debian including 1 source packages (gitlab), 1 status rows across 1 suites (sid): resolved 1. https://security-tracker.debian.org/tracker/CVE-2025-12653

Affected software / configurations for CVE-2025-12653

Vendor Product Version Raw CPE
gitlab gitlab >= 18.3.0, < 18.4.5 cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
gitlab gitlab >= 18.3.0, < 18.4.5 cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*
gitlab gitlab >= 18.5.0, < 18.5.3 cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
gitlab gitlab >= 18.5.0, < 18.5.3 cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*
gitlab gitlab 18.6.0 cpe:2.3:a:gitlab:gitlab:18.6.0:*:*:*:community:*:*:*
gitlab gitlab 18.6.0 cpe:2.3:a:gitlab:gitlab:18.6.0:*:*:*:enterprise:*:*:*

References for CVE-2025-12653

cvelogic Threat Intelligence