# CVE-2026-4338: ActivityPub Routing < 8.0.2 - Unauthenticated Drafts/Scheduled/Pending Posts Disclosure

> Unauthenticated attackers can access drafts, scheduled, and pending posts in the ActivityPub WordPress plugin due to improper filtering.

- **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 8 Apr 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-v6vj-m59r-f4gf

## What is CVE-2026-4338?

CVE-2026-4338 is a high-severity vulnerability in Unknown ActivityPub, published on 8 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The ActivityPub WordPress plugin before 8.0.2 does not properly filter posts to be displayed, allowed unauthenticated users to access drafts/scheduled/pending posts

## Which versions are affected by CVE-2026-4338?

It affects 1 product.


Products: Automattic Activitypub.

## How do I fix CVE-2026-4338?

No fix has been published for CVE-2026-4338 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-4338 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-4338 exists.

## Other vulnerabilities in Unknown ActivityPub

- [CVE-2023-3746](https://insights.sbomify.com/CVE-2023-3746/): ActivityPub for WordPress < 1.0.1 - Contributor+ Stored XSS (medium 5.4)
- [CVE-2023-5057](https://insights.sbomify.com/CVE-2023-5057/): ActivityPub for WordPress < 1.0.0 - Contributor+ Stored XSS (medium 5.4)
- [CVE-2023-3706](https://insights.sbomify.com/CVE-2023-3706/): ActivityPub for WordPress < 1.0.0 - Subscriber+ Arbitrary Post Title Disclosure (medium 4.3)
- [CVE-2023-3707](https://insights.sbomify.com/CVE-2023-3707/): ActivityPub for WordPress < 1.0.0 - Subscriber+ Arbitrary Post Content Disclosure (medium 4.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-4338 and fix it if it is affected.

What it is: CVE-2026-4338 is a high-severity vulnerability in Unknown ActivityPub, published on 8 Apr 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-2026-4338 exists.

Affected product: Unknown ActivityPub. 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-2026-4338/ (Markdown: https://insights.sbomify.com/CVE-2026-4338/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-4338
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-4338
- OSV: https://osv.dev/vulnerability/CVE-2026-4338

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-4338/
Summaries are generated and may contain mistakes; the official description above is the record.