| Plugin Name | Ravelry Designs Widget |
|---|---|
| Type of Vulnerability | Cross-Site Scripting (XSS) |
| CVE Number | CVE-2026-1903 |
| Urgency | Low |
| CVE Publish Date | 2026-02-13 |
| Source URL | CVE-2026-1903 |
Stored XSS in Ravelry Designs Widget (≤1.0.0): What happened, why it matters, and how to respond
Author: Hong Kong Security Research Team — Date: 2026-02-13
TL;DR — A stored Cross‑Site Scripting (XSS) vulnerability (CVE‑2026‑1903) was disclosed in the Ravelry Designs Widget WordPress plugin (versions ≤ 1.0.0). An authenticated user with Contributor privileges can inject malicious script via the sb_ravelry_designs shortcode “layout” attribute that is stored in post content and rendered to site visitors. Impact is limited by required privilege and user interaction, but exploitation can result in session theft, phishing, and site defacement. This post explains the technical root cause, impact scenarios, detection and hunting steps, immediate mitigations you can apply today, recommended WAF/virtual patching rules, and developer fixes to permanently close the hole.
Table of contents
- Summary and affected versions
- Vulnerability technical analysis (root cause)
- Exploitation proof-of-concept (conceptual, sanitized)
- Real‑world impact and threat model
- Detection and hunting — how to find if you were hit
- Immediate mitigations for site owners (step‑by‑step)
- WAF and virtual patching (ready-to-apply rules)
- Developer remediation — secure code snippets and patterns
- Longer‑term hardening and operational recommendations
- Incident response checklist (quick reference)
- Conclusion and references
Summary and affected versions
- Software: Ravelry Designs Widget — WordPress plugin
- Affected versions: ≤ 1.0.0
- Vulnerability class: Stored Cross‑Site Scripting (Stored XSS)
- Vector: sb_ravelry_designs shortcode — layout attribute
- Required privilege: Contributor (authenticated)
- CVE: CVE‑2026‑1903
- CVSSv3 Base Score: 6.5 (User interaction required, limited by privilege)
Summary: The plugin accepts an unfiltered layout attribute on the sb_ravelry_designs shortcode, stores it in wp_posts.post_content, and later outputs it without appropriate escaping. A Contributor can therefore inject markup that executes when a visitor views the rendered post.
Vulnerability technical analysis (root cause)
Shortcodes are a common WordPress mechanism to embed dynamic content. Any data coming from users — including shortcode attributes — must be treated as untrusted. The secure approach is:
- Validate and sanitize inputs when accepting them.
- Escape outputs at render time according to the output context (HTML attribute, HTML body, JavaScript, URL, etc.).
In this case the plugin:
- Registers
sb_ravelry_designs. - Accepts a
layoutattribute for presentation control. - Fails to sanitize/validate the attribute value supplied by a content author.
- Stores the raw attribute in post content.
- Prints the attribute into markup during rendering without escaping (for example, directly into an HTML attribute or fragment).
That allows values such as '">' or onerror=… to be included in rendered pages, producing stored XSS. Contributor privilege matters because contributors can add/edit post content; if that content is published (manually or automatically) the payload becomes visible to visitors.
Root cause: unsanitized input stored and printed into an output context without proper escaping.
Exploitation proof-of-concept (conceptual, sanitized)
The following conceptual PoC is intentionally non-weaponized and intended for defensive testing in a controlled environment only.
Normal shortcode usage:
[sb_ravelry_designs layout="DEFAULT"]Malicious contributor edits draft to:
[sb_ravelry_designs layout='">If the plugin renders:
...