# CVE-2026-0688: Webmention <= 5.6.2 - Authenticated (Subscriber+) Server-Side Request Forgery

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

- **Severity:** Medium 6.4 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Apr 2026
- **Updated:** 8 Apr 2026
- **Also known as:** GHSA-wjf6-53j2-2f8c

## What is CVE-2026-0688?

CVE-2026-0688 is a medium-severity server-side request forgery vulnerability in pfefferle Webmention, published on 2 Apr 2026. Any signed-in user can exploit it over the network, 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 via the 'Tools::read' function. This makes it possible for authenticated attackers, with Subscriber-level access and above, 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-2026-0688?


## How do I fix CVE-2026-0688?

No fix has been published for CVE-2026-0688 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-0688 being exploited?

There is no known exploitation of CVE-2026-0688 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-0688 and fix it if it is affected.

What it is: CVE-2026-0688 is a medium-severity server-side request forgery vulnerability in pfefferle Webmention, published on 2 Apr 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-2026-0688 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-2026-0688/ (Markdown: https://insights.sbomify.com/CVE-2026-0688/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-0688
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-0688
- OSV: https://osv.dev/vulnerability/CVE-2026-0688

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-0688/
Summaries are generated and may contain mistakes; the official description above is the record.