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.

Sources and references

Verified primary and authoritative sources

CVE-2026-8698 CVE Program record
Publisher, destination, and source semantics verified

URL: https://www.cve.org/CVERecord?id=CVE-2026-8698

CVE Program - Official CVE Program record with source-provided CVE metadata.
CVE-2026-8698 NVD vulnerability detail
Publisher, destination, and source semantics verified

URL: https://nvd.nist.gov/vuln/detail/CVE-2026-8698

NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

Source reference
Unverified legacy reference

URL: https://plugins.trac.wordpress.org/browser/cryptocurrency-prijsvergelijking-widget/trunk/functions.php

[email protected]
Source reference
Unverified legacy reference

URL: https://plugins.trac.wordpress.org/browser/cryptocurrency-prijsvergelijking-widget/trunk/functions.php

[email protected]

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.