# CVE-2026-77143: Broken Access Control in extension "Forum" (pforum)

> Attackers can overwrite public forum topic content by submitting unauthorized update requests, requiring no special privileges or configuration.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 25 Aug 2026
- **Updated:** 26 Aug 2026
- **Also known as:** GHSA-7mp3-wcqf-gf22

## What is CVE-2026-77143?

CVE-2026-77143 is a high-severity missing authorization vulnerability in TYPO3 Extension "Forum", published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The frontend topic editing flow does not verify on the server side that the requesting visitor owns the topic being modified. As a result, a visitor who knows the identifier of a topic from the public forum can submit a modified update request for that topic directly and overwrite its content, without the application confirming ownership. Topic identifiers are visible in the public forum listing, and exploitation requires no privileged access or non-default configuration.

Weakness: CWE-862 (Missing Authorization), CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-77143?


## How do I fix CVE-2026-77143?

No fix has been published for CVE-2026-77143 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-77143 being exploited?

There is no known exploitation of CVE-2026-77143 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-77143 and fix it if it is affected.

What it is: CVE-2026-77143 is a high-severity missing authorization vulnerability in TYPO3 Extension "Forum", published on 25 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-77143 in the wild and no public exploit code.

Affected product: TYPO3 Extension "Forum". 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-2026-77143/ (Markdown: https://insights.sbomify.com/CVE-2026-77143/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-77143
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-77143
- OSV: https://osv.dev/vulnerability/CVE-2026-77143

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-77143/
Summaries are generated and may contain mistakes; the official description above is the record.