SSRF in Pfefferle Webmention

CVE-2026-0686

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.

Vulnerability class: SSRF (Server-Side Request Forgery)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (20.9th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 21st percentile — 20.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-0686: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-0686?
CVE-2026-0686 is a high-severity vulnerability in Pfefferle Webmention, classified under Server-Side Request Forgery (SSRF). CVSS score: 7.2/10. Published 2026-04-02.
How severe is CVE-2026-0686?
High severity. CVSS v3 base score is 7.2 out of 10.