CVE-2025-2256 | Improper Validation of Specified Quantity in Input in GitLab

An issue has been discovered in GitLab CE/EE affecting all versions from 7.12 before 18.1.6, 18.2 before 18.2.6, and 18.3 before 18.3.2 that could have allowed unauthorized users to render the GitLab instance unresponsive to legitimate users by sending multiple concurrent large SAML responses.

Published: 2025-09-12 Last update: 2025-09-20 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-2256 is rated Moderate Risk (43.3/100): CVSS High severity, with low exploitation likelihood (EPSS 0.47%). Review affected assets and schedule remediation.

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-2025-2256

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 2026-06-15 0.05% 0.47% +0.42%
2 2026-05-29 0.04% 0.05% +0.01%
3 2026-02-06 — 0.04% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-2256

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H 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:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-2256

OS Trackers for CVE-2025-2256

vendor priority summary link
debian not yet assigned CVE-2025-2256 not yet assigned priority: Debian including 1 source packages (gitlab), 1 status rows across 1 suites (sid): open 1. https://security-tracker.debian.org/tracker/CVE-2025-2256

Affected software / configurations for CVE-2025-2256

Vendor Product Version Raw CPE
gitlab gitlab >= 7.12.0, < 18.1.6 cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
gitlab gitlab >= 7.12.0, < 18.1.6 cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*
gitlab gitlab >= 18.2.0, < 18.2.6 cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
gitlab gitlab >= 18.2.0, < 18.2.6 cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*
gitlab gitlab >= 18.3.0, < 18.3.2 cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*
gitlab gitlab >= 18.3.0, < 18.3.2 cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*

References for CVE-2025-2256

cvelogic Threat Intelligence