CVE-2021-4191
Status: ModifiedMedium (5.3)—💥 Exploit
An issue has been discovered in GitLab CE/EE affecting versions 13.0 to 14.6.5, 14.7 to 14.7.4, and 14.8 to 14.8.2. Private GitLab instances with restricted sign-ups may be vulnerable to user enumeration to unauthenticated users through the GraphQL API.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- Base score: 5.3
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 80%
- Percentile among all scored CVEs: 100
- Score date: 10/7/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
💥 Public exploits
Exploit code or detection templates are publicly available. This is not the same as confirmed active exploitation (KEV), but it raises the risk: patch with priority.
- Nuclei template (automated mass detection) · GitLab GraphQL API User Enumeration
- Proof of concept on GitHub (unverified) · List of proofs of concept on GitHub
⚠️ GitHub proofs of concept are not verified: some are fake or contain malware. Never run them outside an isolated lab.
Affected technologies (1)
CWEs
- NVD-CWE-noinfo
References
- https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-4191.json
- https://gitlab.com/gitlab-org/gitlab/-/issues/343898
- https://hackerone.com/reports/1089609
- https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-4191.json
- https://gitlab.com/gitlab-org/gitlab/-/issues/343898
- https://hackerone.com/reports/1089609
Raw JSON (NVD)
Show
{
"id": "CVE-2021-4191",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 5,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
"authentication": "NONE",
"integrityImpact": "NONE",
"accessComplexity": "LOW",
"availabilityImpact": "NONE",
"confidentialityImpact": "PARTIAL"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 10,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "cve@gitlab.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.3,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 1.4,
"exploitabilityScore": 3.9
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.3,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "LOW"
},
"impactScore": 1.4,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "cve@gitlab.com",
"affectedData": [
{
"vendor": "GitLab",
"product": "GitLab",
"versions": [
{
"status": "affected",
"version": ">=14.8, <14.8.2"
},
{
"status": "affected",
"version": ">=14.7, <14.7.4"
},
{
"status": "affected",
"version": ">=13.0, <14.6.5"
}
]
}
]
}
],
"published": "2022-03-28T19:15:08.093",
"references": [
{
"url": "https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-4191.json",
"tags": [
"Vendor Advisory"
],
"source": "cve@gitlab.com"
},
{
"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/343898",
"tags": [
"Broken Link"
],
"source": "cve@gitlab.com"
},
{
"url": "https://hackerone.com/reports/1089609",
"tags": [
"Permissions Required",
"Third Party Advisory"
],
"source": "cve@gitlab.com"
},
{
"url": "https://gitlab.com/gitlab-org/cves/-/blob/master/2021/CVE-2021-4191.json",
"tags": [
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://gitlab.com/gitlab-org/gitlab/-/issues/343898",
"tags": [
"Broken Link"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://hackerone.com/reports/1089609",
"tags": [
"Permissions Required",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "An issue has been discovered in GitLab CE/EE affecting versions 13.0 to 14.6.5, 14.7 to 14.7.4, and 14.8 to 14.8.2. Private GitLab instances with restricted sign-ups may be vulnerable to user enumeration to unauthenticated users through the GraphQL API."
},
{
"lang": "es",
"value": "Se ha detectado un problema en GitLab CE/EE afectando las versiones 13.0 a 14.6.5, 14.7 a 14.7.4 y 14.8 a 14.8.2. Las instancias privadas de GitLab con registros restringidos pueden ser vulnerables a una enumeración de usuarios a usuarios no autenticados mediante la API GraphQL"
}
],
"lastModified": "2026-06-17T04:19:11.420",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E86DDC12-65BD-493C-8682-9FB31C88B266",
"versionEndExcluding": "14.6.5",
"versionStartIncluding": "13.0.0"
},
{
"criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9D503931-6E2D-4918-A184-82F4238FBD88",
"versionEndExcluding": "14.6.5",
"versionStartIncluding": "13.0.0"
},
{
"criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DA9B6C10-6253-4C3F-8897-F0080B23414C",
"versionEndExcluding": "14.7.4",
"versionStartIncluding": "14.7.0"
},
{
"criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9218E9A3-C643-4987-BF82-727E0AB868E5",
"versionEndExcluding": "14.7.4",
"versionStartIncluding": "14.7.0"
},
{
"criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:community:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6AE10377-91D9-4F0F-984C-C36C8942F643",
"versionEndExcluding": "14.8.2",
"versionStartIncluding": "14.8"
},
{
"criteria": "cpe:2.3:a:gitlab:gitlab:*:*:*:*:enterprise:*:*:*",
"vulnerable": true,
"matchCriteriaId": "66B9F17C-CF83-47DD-8D56-0FE2FE384D86",
"versionEndExcluding": "14.8.2",
"versionStartIncluding": "14.8"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cve@gitlab.com"
}