CVE-2026-8879

CVE-2026-8879

High · published June 3, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
42.6
In the wild
Unconfirmed
What it is

Version 3.0.7 of the Securly Chrome Extension dynamically registers content13.min.js as a content script via chrome.scripting.registerContentScripts() at runtime. This script is NOT declared in manifest.json and bypasses Chrome Web Store static security review. It runs on all URLs and immediately hides all page content, creates a full-page overlay, pauses all videos, and only restores content when the service worker confirms the page passes filtering. If Securly's servers are unreachable, pages remain indefinitely hidden.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00509 · 42.6th percentile
Published
2026-06-03T18:11Z
EPSS history
Timeline
  • 03 JUN 18:11Z
    CVE-2026-8879
    cvelistv5