# CVE-2026-0686: Webmention <= 5.6.2 - Unauthenticated Blind Server-Side Request Forgery

> Unauthenticated attackers can exploit a Server-Side Request Forgery flaw in the Webmention WordPress plugin to query and modify internal services.

- **Severity:** High 7.2 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/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:** 2 Apr 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-pwm7-wr54-2jxv

## What is CVE-2026-0686?

CVE-2026-0686 is a high-severity server-side request forgery vulnerability in pfefferle Webmention, published on 2 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

The Webmention plugin for WordPress is vulnerable to Server-Side Request Forgery in all versions up to, and including, 5.6.2 in the 'MF2::parse_authorpage' function via the 'Receiver::post' function. This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-0686?


## How do I fix CVE-2026-0686?

No fix has been published for CVE-2026-0686 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-0686 being exploited?

There is no known exploitation of CVE-2026-0686 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-0686 and fix it if it is affected.

What it is: CVE-2026-0686 is a high-severity server-side request forgery vulnerability in pfefferle Webmention, published on 2 Apr 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-2026-0686 in the wild and no public exploit code.

Affected product: pfefferle Webmention. 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-2026-0686/ (Markdown: https://insights.sbomify.com/CVE-2026-0686/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-0686
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0686
- OSV: https://osv.dev/vulnerability/CVE-2026-0686

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-0686/
Summaries are generated and may contain mistakes; the official description above is the record.