CVE-2026-9132

Published Jun 30, 2026

Last updated 7 days ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2026-9132 is an authorization bypass vulnerability found in GitHub Enterprise Server. The flaw specifically resides within the Copilot pull request description diff summary endpoint. This endpoint was designed to accept cross-repository comparison ranges and render the resulting diffs without adequately verifying if the requesting user had authorization to view the target repository. This oversight allowed an authenticated user, who possessed read access to at least one repository on the instance, to exploit the endpoint. By doing so, they could read source code from private repositories to which they otherwise did not have access. The vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was addressed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4.

Description
A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user to read source code from private repositories they did not have access to. The Copilot pull request description diff summary endpoint accepted a cross-repository comparison range and rendered the resulting diff without verifying that the requesting user was authorized to view the target repository. Exploitation required an authenticated account on the instance with read access to at least one repository to use as the comparison base. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.21 and was fixed in versions 3.17.17, 3.18.11, 3.19.8, and 3.20.4. This vulnerability was reported via the GitHub Bug Bounty program.
Source
product-cna@github.com
NVD status
Analyzed
Products
enterprise_server

Risk scores

CVSS 4.0

Type
Secondary
Base score
6
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/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
Severity
MEDIUM

CVSS 3.1

Type
Primary
Base score
6.5
Impact score
3.6
Exploitability score
2.8
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Severity
MEDIUM

Weaknesses

product-cna@github.com
CWE-862

Social media

Hype score
Not currently trending

Configurations