# CVE-2026-15783: Missing authorization in Enterprise Server

> Authenticated users with write access can read private repository metadata from unauthorized repositories due to missing authorization checks.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 17 Jul 2026
- **Updated:** 17 Jul 2026
- **Also known as:** GHSA-qhvh-xjh2-7c8c

## What is CVE-2026-15783?

CVE-2026-15783 is a medium-severity missing authorization vulnerability in GitHub Enterprise Server, published on 17 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A missing authorization vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with write access to any repository to read metadata from private repositories they did not have access to, including private repository owners and names, branch names, commit SHAs, commit messages, and the pushing actor. The delegated bypass endpoint resolved a rule suite directly from an attacker-supplied, encoded identifier without verifying that the requesting user could read the rule suite's repository, and because these identifiers are sequential an attacker could enumerate them across the instance. This vulnerability affected all versions of GitHub Enterprise Server prior to 3.22 and was fixed in versions 3.17.18, 3.18.12, 3.19.9, 3.20.5, and 3.21.3. This vulnerability was reported via the GitHub Bug Bounty program.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-15783?


## How do I fix CVE-2026-15783?

No fix has been published for CVE-2026-15783 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15783 being exploited?

There is no known exploitation of CVE-2026-15783 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15783 and fix it if it is affected.

What it is: CVE-2026-15783 is a medium-severity missing authorization vulnerability in GitHub Enterprise Server, published on 17 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-15783 in the wild and no public exploit code.

Affected product: GitHub Enterprise Server. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-15783/ (Markdown: https://insights.sbomify.com/CVE-2026-15783/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15783
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15783
- OSV: https://osv.dev/vulnerability/CVE-2026-15783

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15783/
Summaries are generated and may contain mistakes; the official description above is the record.