CVE-2026-14340
Last modified
CVE-2026-14340 is a medium-severity vulnerability rated 5/10 on the CVSS scale. An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed a user-to-server token scoped to a GitHub App installation to perform certain write operations on public repositories outside the token's intended scope. This was possible because the authorization check only verified that the installation had read permissions on the target repository rather than verifying that the token's installation was explicitly granted access to that repository. EPSS estimates a 0.28% chance of exploitation in the next 30 days.
Description
An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed a user-to-server token scoped to a GitHub App installation to perform certain write operations on public repositories outside the token's intended scope. This was possible because the authorization check only verified that the installation had read permissions on the target repository rather than verifying that the token's installation was explicitly granted access to that repository. An attacker who obtained a victim's user-to-server token could create issues, issue comments, commit comments, and private vulnerability reports on any public repository, appearing as the victim user with no indication of the app involvement. This vulnerability was fixed by adding a repository scope check for user-to-server tokens issued by global apps. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.21.2, 3.20.4, 3.19.8, 3.18.11, 3.17.17, 3.16.20. This vulnerability was reported via the GitHub Bug Bounty program.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/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
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| Github | Enterprise Server | < 3.16.20 |
| Github | Enterprise Server | >= 3.17.0, < 3.17.17 |
| Github | Enterprise Server | >= 3.18.0, < 3.18.11 |
| Github | Enterprise Server | >= 3.19.0, < 3.19.8 |
| Github | Enterprise Server | >= 3.20.0, < 3.20.4 |
| Github | Enterprise Server | >= 3.21.0, < 3.21.2 |
References
- https://docs.github.com/en/enterprise-server@3.16/admin/release-notes#3.16.20Product, Release Notes
- https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.17Product, Release Notes
- https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.11Product, Release Notes
- https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.8Product, Release Notes
- https://docs.github.com/en/enterprise-server@3.20/admin/release-notes#3.20.4Product, Release Notes
- https://docs.github.com/en/enterprise-server@3.21/admin/release-notes#3.21.2Product, Release Notes
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-14340?
How severe is CVE-2026-14340?
How do I fix CVE-2026-14340?
How Strix Helps
- Uncovering a hidden BOLA in Appsmith's snapshot logicStrix autonomously discovered a BOLA/IDOR vulnerability in Appsmith's snapshot deletion path.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-14332The Ecwid by Lightspeed Ecommerce Shopping Cart WordPress pl…5.4
- CVE-2026-14333The Demi WordPress plugin before 0.0.7 stores its full-site…7.5
- CVE-2026-14334The Booking calendar, Appointment Booking System WordPress p…8.8
- CVE-2026-14336PIA's OIDC issuer allowlist for Jenkins tokens uses a bare s…8.2
- CVE-2026-14337Pega Platform versions 23.1.0 through 25.1.3 are affected by…4.6
- CVE-2026-1434Omega-PSIR is vulnerable to Reflected XSS via the lang param…6.1
- CVE-2026-14341GitLab has remediated an issue in GitLab CE/EE affecting all…4.9
- CVE-2026-14342The Mail Mint – Email Marketing, Newsletter, Email Automatio…4.9
- CVE-2026-14343The Download Manager plugin for WordPress is vulnerable to S…6.4
- CVE-2026-14345The WPFunnels – Funnel Builder for WooCommerce with Checkout…9.8
- CVE-2026-1435Not properly invalidated session vulnerability in Graylog We…9.8
- CVE-2026-14350IBM Cloud Pak for Data System 11.3.0.2 through Interim Fix 0…5.3
Are you affected by CVE-2026-14340?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST
