# CVE-2026-70556: Hubzilla version prior to 11.4 CSRF via OAuth2 /authorize Endpoint App Registration

> Attackers can exploit CSRF in Hubzilla to register malicious OAuth2 apps, potentially intercepting authorization codes and compromising user accounts.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/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:** A user has to click or open something
- **Fix available:** No
- **Published:** 6 Aug 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-q8qh-69f5-v25q

## What is CVE-2026-70556?

CVE-2026-70556 is a medium-severity vulnerability in Hubzilla, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Hubzilla  versions prior to 11.4 contains a cross-site request forgery vulnerability in the OAuth2 /authorize endpoint handled by Zotlabs\Module\Authorize::post() that allows unauthenticated attackers to register arbitrary OAuth2 applications under an authenticated user's account by submitting a cross-origin POST request without CSRF token or Origin/Referer validation. Attackers can craft a malicious HTML form that autosubmits attacker-chosen OAuth2 parameters including client_id, client_secret, redirect_uri, and scope to silently register a persistent OAuth2 application, enabling interception of future OAuth2 authorization codes when the victim later authenticates against the attacker-controlled client.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2026-70556?


## How do I fix CVE-2026-70556?

No fix has been published for CVE-2026-70556 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-70556 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-70556 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-70556 and fix it if it is affected.

What it is: CVE-2026-70556 is a medium-severity vulnerability in Hubzilla, published on 6 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-70556 exists.

Affected product: Hubzilla. 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-2026-70556/ (Markdown: https://insights.sbomify.com/CVE-2026-70556/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-70556
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-70556
- OSV: https://osv.dev/vulnerability/CVE-2026-70556

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-70556/
Summaries are generated and may contain mistakes; the official description above is the record.