PatchSiren cyber security CVE debrief
CVE-2026-8698 cryptoprijzen CVE debrief
A stored cross-site scripting (XSS) vulnerability exists in the Cryptocurrency Prijsvergelijking Widget plugin for WordPress, version 1.0. The flaw resides in the `as_get_coin_shortcode()` function, which fails to escape the 'width' and 'height' shortcode attributes before rendering them within the style attribute of an iframe element. An attacker with contributor-level access or higher can inject malicious JavaScript payloads that execute when any user visits a compromised page. The vulnerability was disclosed on 2026-05-27 and carries a CVSS 3.1 score of 6.4 (Medium severity). No known exploitation in the wild or ransomware campaign use has been documented.
- Vendor
- cryptoprijzen
- Product
- Cryptocurrency Prijsvergelijking Widget
- CVSS
- MEDIUM 6.4
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-05-27
- Original CVE updated
- 2026-05-27
- Advisory published
- 2026-05-27
- Advisory updated
- 2026-05-27
Who should care
WordPress site administrators running the Cryptocurrency Prijsvergelijking Widget plugin; security teams managing multi-author WordPress installations; developers maintaining shortcode-based plugins
Technical summary
The plugin's shortcode handler directly interpolates user-supplied width and height attributes into an HTML style attribute without sanitization. A payload such as '100px;onload=alert(1) x=' breaks out of the style context and injects an event handler. The vulnerability requires authenticated access at contributor level or above to exploit, limiting exposure but not eliminating risk in multi-author WordPress environments. The CVSS vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N reflects network attack vector, low attack complexity, low privileges required, no user interaction, changed scope, and low impacts to confidentiality and integrity.
Defensive priority
medium
Recommended defensive actions
- Update the Cryptocurrency Prijsvergelijking Widget plugin to a patched version when available from the WordPress plugin repository
- Review and remove any suspicious shortcode usage in posts or pages, particularly those with unusual width or height attribute values
- Implement Content Security Policy (CSP) headers to mitigate impact of any stored XSS payloads
- Conduct code review of custom shortcode implementations for similar output escaping deficiencies
- Apply principle of least privilege by restricting contributor and author roles where possible
Evidence notes
The vulnerability is attributed to missing output escaping (esc_attr()) in the shortcode handler function. Wordfence security advisory and WordPress plugin repository source code references confirm the affected code locations at lines 138 and 157 of functions.php.
Official resources
2026-05-27