# CVE-2026-42070: MantisBT: Authorization Bypass in Bugnote Editing via Issue Update API

> Attackers with updater privileges can modify other users' bugnotes via the API, bypassing stricter authorization checks.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/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:** 28 May 2026
- **Updated:** 2 Jun 2026
- **Also known as:** GHSA-pq86-j2c2-47f6

## What is CVE-2026-42070?

CVE-2026-42070 is a medium-severity missing authorization vulnerability in mantisbt, published on 28 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. Prior to 2.28.2, the mc_issue_update() function in MantisBT allows users having update_bug_threshold access (UPDATER, with default settings) to edit, change view state, and modify time tracking on bugnotes belonging to other users — bypassing the default DEVELOPER (level 55) threshold required by the dedicated mc_issue_note_update() function. This vulnerability is fixed in 2.28.2.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-42070?

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


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `mantisbt/mantisbt` | Packagist | All versions | 2.28.2 |
| `mantisbt/mantisbt` | Packagist | All versions | 2.28.2 |

## How do I fix CVE-2026-42070?

Upgrade mantisbt/mantisbt to 2.28.2 or later.

## Is CVE-2026-42070 being exploited?

There is no known exploitation of CVE-2026-42070 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-42070 and fix it if it is affected.

What it is: CVE-2026-42070 is a medium-severity missing authorization vulnerability in mantisbt, published on 28 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-2026-42070 in the wild and no public exploit code.

Affected packages and fixed versions:
- mantisbt/mantisbt (Packagist): affected all versions; fixed in 2.28.2
- mantisbt/mantisbt (Packagist): affected all versions; 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-2026-42070/ (Markdown: https://insights.sbomify.com/CVE-2026-42070/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-42070
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42070
- OSV: https://osv.dev/vulnerability/CVE-2026-42070

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-42070/
Summaries are generated and may contain mistakes; the official description above is the record.