CVE-2026-19118

A time-of-check time-of-use race condition vulnerability was identified in GitHub Enterprise Server that allowed remote code execution. Exploitation required an authenticated user with write access to a repository and precise timing of concurrent upload requests. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.20, 3.18.14, 3.19.11, 3.20.7, and 3.21.5. This vulnerability was reported via the GitHub Bug Bounty program.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.6 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.20	Release Notes Vendor Advisory
https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.14	Release Notes Vendor Advisory
https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.11	Release Notes Vendor Advisory
https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.7	Release Notes Vendor Advisory
https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.5	Release Notes Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:github:enterprise_server::::::::
	cpe:2.3:a:github:enterprise_server::::::::
	cpe:2.3:a:github:enterprise_server::::::::
	cpe:2.3:a:github:enterprise_server::::::::
	cpe:2.3:a:github:enterprise_server::::::::

History

No history.

Information

Published : 2026-09-01 22:17

Updated : 2026-09-08 13:08

NVD link : CVE-2026-19118

Mitre link : CVE-2026-19118

CVE.ORG link : CVE-2026-19118

JSON object : View

Products Affected

github

enterprise_server

CWE

CWE-367

Time-of-check Time-of-use (TOCTOU) Race Condition

{"id": "CVE-2026-19118", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-19118", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-09-02T13:09:42.799923Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 1.6}], "cvssMetricV40": [{"type": "Secondary", "source": "product-cna@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 7.7, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "LOW", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "product-cna@github.com", "affectedData": [{"vendor": "GitHub", "product": "Enterprise Server", "versions": [{"status": "affected", "changes": [{"at": "3.17.20", "status": "unaffected"}], "version": "3.17.0", "versionType": "semver", "lessThanOrEqual": "3.17.19"}, {"status": "affected", "changes": [{"at": "3.18.14", "status": "unaffected"}], "version": "3.18.0", "versionType": "semver", "lessThanOrEqual": "3.18.13"}, {"status": "affected", "changes": [{"at": "3.19.11", "status": "unaffected"}], "version": "3.19.0", "versionType": "semver", "lessThanOrEqual": "3.19.10"}, {"status": "affected", "changes": [{"at": "3.20.7", "status": "unaffected"}], "version": "3.20.0", "versionType": "semver", "lessThanOrEqual": "3.20.6"}, {"status": "affected", "changes": [{"at": "3.21.5", "status": "unaffected"}], "version": "3.21.0", "versionType": "semver", "lessThanOrEqual": "3.21.4"}, {"status": "unaffected", "version": "3.22.0", "versionType": "semver"}], "defaultStatus": "affected"}]}], "published": "2026-09-01T22:17:11.010", "references": [{"url": "https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.20", "tags": ["Release Notes", "Vendor Advisory"], "source": "product-cna@github.com"}, {"url": "https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.14", "tags": ["Release Notes", "Vendor Advisory"], "source": "product-cna@github.com"}, {"url": "https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.11", "tags": ["Release Notes", "Vendor Advisory"], "source": "product-cna@github.com"}, {"url": "https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.7", "tags": ["Release Notes", "Vendor Advisory"], "source": "product-cna@github.com"}, {"url": "https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.5", "tags": ["Release Notes", "Vendor Advisory"], "source": "product-cna@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "product-cna@github.com", "description": [{"lang": "en", "value": "CWE-367"}]}], "descriptions": [{"lang": "en", "value": "A time-of-check time-of-use race condition vulnerability was identified in GitHub Enterprise Server that allowed remote code execution. Exploitation required an authenticated user with write access to a repository and precise timing of concurrent upload requests. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.20, 3.18.14, 3.19.11, 3.20.7, and 3.21.5. This vulnerability was reported via the GitHub Bug Bounty program."}], "lastModified": "2026-09-08T13:08:54.503", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "C04631D9-CD92-46E8-8629-042A69056FD9", "versionEndExcluding": "3.17.20"}, {"criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E2B8B99C-F249-4A16-A1F2-7D04A4D5CA64", "versionEndExcluding": "3.18.14", "versionStartIncluding": "3.18.0"}, {"criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "5D499465-2F90-4050-BE5E-1340D77D9E07", "versionEndExcluding": "3.19.11", "versionStartIncluding": "3.19.0"}, {"criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "89B7F792-E9C2-4031-91E1-D0F42B058AC0", "versionEndExcluding": "3.20.7", "versionStartIncluding": "3.20.0"}, {"criteria": "cpe:2.3:a:github:enterprise_server:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E89BCFC0-15E1-458C-A6DD-9F647DF9817F", "versionEndExcluding": "3.21.5", "versionStartIncluding": "3.21.0"}], "operator": "OR"}]}], "sourceIdentifier": "product-cna@github.com"}