CVE-2026-8865 | Avalon23 Products Filter for WooCommerce <= 1.1.6 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

The Avalon23 Products Filter for WooCommerce plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'avalon23_qr' shortcode in all versions up to, and including, 1.1.6. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes (notably 'title' and 'fixed_link') which are concatenated directly into single-quoted HTML attributes by the AVALON23_HELPER::draw_html_item() helper without esc_attr() or any other encoding. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Published: 2026-06-24 Last update: 2026-06-25 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-8865 is rated Low Risk (28.8/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.19%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-8865

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-24 0.19%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-8865

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
3.1 2.7 [email protected]

Weakness enumeration for CVE-2026-8865

GitHub Security Advisory for CVE-2026-8865

GHSA-hxr4-2fcj-gcw3 · Severity: medium — The Avalon23 Products Filter for WooCommerce plugin for WordPress is vulnerable to Stored Cross...

Affected software / configurations for CVE-2026-8865

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-8865

cvelogic Threat Intelligence