GitLab Community Edition/Enterprise Edition up to 18.1.5/18.2.5/18.3.1 SAML Response improper validation of specified quantity in input

CVSS Meta Temp Score
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CTI Interest Score
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6.3$0-$5k0.00

Summaryinfo

A vulnerability classified as problematic has been found in GitLab Community Edition and Enterprise Edition up to 18.1.5/18.2.5/18.3.1. Impacted is an unknown function of the component SAML Response Handler. The manipulation leads to improper validation of specified quantity in input. This vulnerability is referenced as CVE-2025-2256. Remote exploitation of the attack is possible. No exploit is available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in GitLab Community Edition and Enterprise Edition up to 18.1.5/18.2.5/18.3.1 and classified as problematic. This issue affects some unknown processing of the component SAML Response Handler. The manipulation with an unknown input leads to a improper validation of specified quantity in input vulnerability. Using CWE to declare the problem leads to CWE-1284. The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties. Impacted is availability. The summary by CVE is:

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.

The weakness was published by yuki_osaki and lambdasawa as 524633. It is possible to read the advisory at about.gitlab.com. The identification of this vulnerability is CVE-2025-2256 since 03/12/2025. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. The technical details are unknown and an exploit is not publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 264596 (GitLab 7.12 < 18.1.6 / 18.2 < 18.2.6 / 18.3 < 18.3.2 (CVE-2025-2256)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 18.1.6, 18.2.6 or 18.3.2 eliminates this vulnerability. The upgrade is hosted for download at about.gitlab.com.

The vulnerability is also documented in the databases at Tenable (264596), EUVD (EUVD-2025-29019) and CERT Bund (WID-SEC-2025-2024). Be aware that VulDB is the high quality 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: 6.4
VulDB Meta Temp Score: 6.3

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.5
CNA Vector (GitLab): 🔒

CVSSv2info

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

Exploitinginfo

Class: Improper validation of specified quantity in input
CWE: CWE-1284 / CWE-703
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: 264596
Nessus Name: GitLab 7.12 < 18.1.6 / 18.2 < 18.2.6 / 18.3 < 18.3.2 (CVE-2025-2256)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Community Edition/Enterprise Edition 18.1.6/18.2.6/18.3.2

Timelineinfo

03/12/2025 CVE reserved
09/12/2025 +183 days Advisory disclosed
09/12/2025 +0 days VulDB entry created
09/12/2025 +0 days VulDB entry last update

Sourcesinfo

Vendor: gitlab.com

Advisory: 524633
Researcher: yuki_osaki, lambdasawa
Status: Confirmed

CVE: CVE-2025-2256 (🔒)
GCVE (CVE): GCVE-0-2025-2256
GCVE (VulDB): GCVE-100-323735
EUVD: 🔒
CERT Bund: WID-SEC-2025-2024 - GitLab: Mehrere Schwachstellen

Entryinfo

Created: 09/12/2025 08:56
Updated: 09/12/2025 22:16
Changes: 09/12/2025 08:56 (67), 09/12/2025 09:49 (1), 09/12/2025 10:22 (7), 09/12/2025 22:16 (2)
Complete: 🔍
Cache ID: 216::103

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