Securly Chrome Extension up to 3.0.7 content13.min.js chrome.scripting.registerContentScripts inclusion of functionality from untrusted control sphere

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.5$0-$5k1.46

Summaryinfo

A vulnerability, which was classified as critical, was found in Securly Chrome Extension up to 3.0.7. This affects the function chrome.scripting.registerContentScripts of the file content13.min.js. Such manipulation leads to inclusion of functionality from untrusted control sphere. This vulnerability is documented as CVE-2026-8879. There is not any exploit available.

Detailsinfo

A vulnerability was found in Securly Chrome Extension up to 3.0.7. It has been rated as critical. Affected by this issue is the function chrome.scripting.registerContentScripts of the file content13.min.js. The manipulation with an unknown input leads to a inclusion of functionality from untrusted control sphere vulnerability. Using CWE to declare the problem leads to CWE-829. The product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere. The impact remains unknown. CVE summarizes:

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 advisory is shared for download at kb.cert.org. This vulnerability is handled as CVE-2026-8879 since 05/18/2026. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 06/03/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.5
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Inclusion of functionality from untrusted control sphere
CWE: CWE-829
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

05/18/2026 CVE reserved
06/03/2026 +16 days Advisory disclosed
06/03/2026 +0 days VulDB entry created
06/03/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: kb.cert.org
Status: Not defined

CVE: CVE-2026-8879 (🔒)
GCVE (CVE): GCVE-0-2026-8879
GCVE (VulDB): GCVE-100-368216

Entryinfo

Created: 06/03/2026 22:13
Changes: 06/03/2026 22:13 (53)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Might our Artificial Intelligence support you?

Check our Alexa App!