CVE-2026-61559Public exploitNetwork attack vectorHinoki check available

Credential theft via unrestricted API URL header

Published Sep 15, 2026 · Updated Sep 15, 2026

Server-side request forgery in GitLab MCP Server before 2.1.27 allows remote authenticated users to steal configured GitLab tokens. The SSE handler and Streamable HTTP parseAuthHeaders path accept X-GitLab-API-URL after syntax-only validation, then getFetchConfig attaches the victim's Private-Token to requests sent to that host. Exploitation requires ENABLE_DYNAMIC_API_URL=true and HTTP-transport access with an accepted authorization token; the stolen token grants the attacker's GitLab API access at the victim's permission level.

CVSS severity9.6
Critical
EPSS probability0.27%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Server-side request forgery in GitLab MCP Server before 2.1.27 allows remote authenticated users to steal configured GitLab tokens. The SSE handler and Streamable HTTP parseAuthHeaders path accept X-GitLab-API-URL after syntax-only validation, then getFetchConfig attaches the victim's Private-Token to requests sent to that host. Exploitation requires ENABLE_DYNAMIC_API_URL=true and HTTP-transport access with an accepted authorization token; the stolen token grants the attacker's GitLab API access at the victim's permission level.

The record

CVE
CVE-2026-61559
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
zereight
Product
GitLab MCP Server
Classifications
CWE-918, T1528
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 0.0.1, < 2.1.27

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

zereight · GitLab MCP Serverversion=>= 0.0.1, < 2.1.27

Published CVSS scores

9.6GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-918Server-Side Request Forgery (SSRF)
T1528Steal Application Access Token

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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