CVE-2026-0686
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedThe 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Webmention plugin for WordPress versions up to 5.6.2 contains an unauthenticated Server-Side Request Forgery (SSRF) vulnerability in the MF2::parse_authorpage function via Receiver::post. Attackers can exploit this to make arbitrary HTTP requests from the server to internal or external services, potentially enabling reconnaissance, data exfiltration, or pivoting to internal systems.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
-
Verify Webmention plugin is installedLog into WordPress admin, go to Plugins > Installed Plugins, and look for 'Webmention' in the list. Alternatively, check the file system for /wp-content/plugins/webmention/ directory.Affected if The Webmention plugin is present in the WordPress installation
-
Check the installed Webmention versionIn WordPress admin, find Webmention in the plugin list and view the version number under the plugin name. Alternatively, check the main plugin file header in /wp-content/plugins/webmention/webmention.php for the 'Version' tag.Affected if The installed version is 5.6.2 or earlier (versions up to and including 5.6.2 are affected)
-
Confirm the REST API receiver endpoint is accessibleMake a GET request to /wp-json/webmention/v1/receiver on the site. This endpoint exposes the Receiver::post function. Use a tool like curl: curl -s https://yourdomain.com/wp-json/webmention/v1/receiverAffected if The endpoint returns a valid response (200/400/405) rather than a 404, indicating the vulnerable function is exposed
-
Check if the plugin is processing external URLsReview server access logs for POST requests to /wp-json/webmention/v1/receiver that contain 'author' or 'url' parameters pointing to external domains. Also check if the WordPress site is making unexpected outbound HTTP requests.Affected if The server is processing webmention submissions from external sources, which triggers the vulnerable MF2::parse_authorpage function
You are affected if the Webmention plugin is installed, active, and running version 5.6.2 or earlier with the REST API endpoint accessible.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate the Webmention plugin to version 5.6.3 or later. If immediate patching is not feasible, consider disabling the plugin or implementing URL allowlisting at the web server/WAF level to restrict outgoing requests to trusted domains only.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-0686 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-0686 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data