# CVE-2026-15516: MacCMS Pro Installation Index.php step5 authorization

> Attackers can bypass authorization in the MacCMS Pro installation module to gain elevated privileges, requiring a software upgrade to fix.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 13 Jul 2026
- **Updated:** 13 Jul 2026
- **Also known as:** GHSA-r7c2-xcmm-m4pr

## What is CVE-2026-15516?

CVE-2026-15516 is a medium-severity authentication bypass vulnerability in MacCMS Pro, published on 13 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was detected in MacCMS Pro up to 2022.1000.3005. Impacted is the function step5 of the file application/install/controller/Index.php of the component Installation Module. The manipulation results in authorization bypass. The attack may be launched remotely. The attack requires a high level of complexity. The exploitability is considered difficult. The exploit is now public and may be used. Upgrading to version 2022.1000.3025 is recommended to address this issue. Upgrading the affected component is recommended.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key), CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-15516?


## How do I fix CVE-2026-15516?

No fix has been published for CVE-2026-15516 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-15516 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15516 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-15516 and fix it if it is affected.

What it is: CVE-2026-15516 is a medium-severity authentication bypass vulnerability in MacCMS Pro, published on 13 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-15516 exists.

Affected product: MacCMS Pro. 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-2026-15516/ (Markdown: https://insights.sbomify.com/CVE-2026-15516/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-15516
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-15516
- OSV: https://osv.dev/vulnerability/CVE-2026-15516

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-15516/
Summaries are generated and may contain mistakes; the official description above is the record.