Reflected HTML injection vulnerability in GitHub Enterprise Server Management Console login page allowed credential theft
Summary
| CVE | CVE-2026-8106 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_P |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-07 22:16:37 UTC |
| Updated | 2026-05-07 22:16:37 UTC |
| Description | A reflected HTML injection vulnerability was identified in the GitHub Enterprise Server Management Console login page that could allow credential theft. The redirect_to query parameter on the /setup/unlock endpoint was reflected into an HTML attribute without proper sanitization, enabling an attacker to inject a form element that could capture administrator credentials. Exploitation required an administrator to click a crafted link and enter their credentials. This vulnerability affected GitHub Enterprise Server versions 3.19.1 through 3.19.5 and 3.20.0 through 3.20.1, and was fixed in versions 3.19.6 and 3.20.2. This vulnerability was reported via the GitHub Bug Bounty program. |
Risk And Classification
Primary CVSS: v4.0 5.9 MEDIUM from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/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
Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 5.9 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 5.9 | MEDIUM | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
ActiveConfidentiality
HighIntegrity
NoneAvailability
NoneSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/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
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | GitHub | Enterprise Server | affected 3.19.1 3.19.5 semver | Not specified |
| CNA | GitHub | Enterprise Server | affected 3.20.0 3.20.1 semver | Not specified |
| CNA | GitHub | Enterprise Server | unaffected 3.19.0 semver | Not specified |
| CNA | GitHub | Enterprise Server | unaffected 3.21.0 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| docs.github.com/en/[email protected]/admin/release-notes | [email protected] | docs.github.com | |
| docs.github.com/en/[email protected]/admin/release-notes | [email protected] | docs.github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: maksyche (en)
There are currently no legacy QID mappings associated with this CVE.