CVE-2026-8879
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk30th percentile - higher than 30% of all known CVEs
Summary
Securly Chrome Extension version 3.0.7 dynamically registers content13.min.js as a content script not declared in manifest.json, bypassing Chrome Web Store static security review. It runs on all URLs, 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.
Risk Assessment
The risk is that the extension may hide all web page content indefinitely if Securly servers are unreachable, potentially causing user disruption and data leakage if users attempt to bypass this behavior.
Recommendation
It is recommended to immediately update the Securly extension to the latest version that fixes this vulnerability, or temporarily disable the extension until a patch is released.
Other vulnerabilities in Securly Chrome Extension
See all- CVE-2026-8889High
Version 3.0.7 of the Securly Chrome Extension uses deprecated SHA-1 hashing for IWF CSAM URL matching (25,020 hashes) and CIPA blocklist matching (12,352 hashes).
- CVE-2026-8888High
Securly Chrome Extension version 3.0.7 downloads config.json over HTTP and compiles server-provided patterns as JavaScript regular expressions via new RegExp() without complexity validation. An on-path attacker can inject patterns causing catastrophic backtracking, resulting in denial of service on all browsing.
- CVE-2026-8881High
Securly Chrome Extension version 3.0.7 uses EVP_BytesToKey with MD5 and a single iteration for AES encryption. MD5 has been broken since 2004 and a single iteration provides no key stretching, weakening the encryption.
- CVE-2026-8878High
Version 3.0.7 of the Securly Chrome Extension exposes multiple publicly accessible endpoints that allow unauthenticated access to sensitive data. The exposed information consists of SHA-1 hashes obfuscated with a simple Caesar cipher that can be easily reversed.
- CVE-2026-8876High
Version 3.0.7 of the Securly Chrome Extension contains hardcoded, plaintext AES passphrases in securly.min.js. These keys decrypt crisis alert keyword data and intervention site data.
- CVE-2026-8874High
Securly Chrome Extension version 3.0.7 downloads JSON files containing crisis alert keywords and filtering rules over unencrypted HTTP via the Fetch API. Other endpoints in the same extension correctly fetch IWF and CIPA data over HTTPS, demonstrating an inconsistent TLS implementation.
Original NVD description (English source)
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.