# CVE-2026-34579: MantisBT has an authorization bypass via private issue monitoring

> Attackers with project access can monitor private issues via crafted requests, receiving email notifications that disclose private issue metadata and content.

- **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:** Yes
- **Published:** 19 May 2026
- **Updated:** 20 May 2026
- **Also known as:** GHSA-ggw7-9675-6v4v

## What is CVE-2026-34579?

CVE-2026-34579 is a medium-severity missing authorization vulnerability in mantisbt, published on 19 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Mantis Bug Tracker (MantisBT) is an open source issue tracker. Versions 2.28.1 and prior are vulnerable to Authorization Bypass through the private issue monitoring feature . Using a crafted POST request to bug_monitor_add.php, a user with project-level access can add themselves as a monitor for a private issue they do not have access to. Despite displaying an Access Denied error, the application accepts the request and creates a monitor relationship for the private issue. Direct access to the private issue remains blocked, but the user will receive email notifications for updates, leading to disclosure of the private issue's metadata and content. This issue has been fixed in version 2.28.2.

Weakness: CWE-863 (Incorrect Authorization), CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-34579?

2 open source packages ship an affected version, including mantisbt/mantisbt.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mantisbt/mantisbt` | Packagist | From 2.26.1 | 2.28.2 |
| `mantisbt/mantisbt` | Packagist | From 2.26.1 | 2.28.2 |

## How do I fix CVE-2026-34579?

Upgrade mantisbt/mantisbt to 2.28.2 or later.

## Is CVE-2026-34579 being exploited?

There is no known exploitation of CVE-2026-34579 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34579 and fix it if it is affected.

What it is: CVE-2026-34579 is a medium-severity missing authorization vulnerability in mantisbt, published on 19 May 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-2026-34579 in the wild and no public exploit code.

Affected packages and fixed versions:
- mantisbt/mantisbt (Packagist): affected from 2.26.1; fixed in 2.28.2
- mantisbt/mantisbt (Packagist): affected from 2.26.1; fixed in 2.28.2

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-2026-34579/ (Markdown: https://insights.sbomify.com/CVE-2026-34579/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34579
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34579
- OSV: https://osv.dev/vulnerability/CVE-2026-34579

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34579/
Summaries are generated and may contain mistakes; the official description above is the record.