Improper Authorization Vulnerability in Adblock for Youtube Chrome Extension
CVE-2026-19986

5.3MEDIUM

Key Information:

Vendor

AdBlock Ltd.

Status
Adblock For Youtube Extension
Vendor
CVE Published:
17 August 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-19986?

A vulnerability has been detected in the Adblock for Youtube Extension version 7.2.1 for Chrome, originating from a flaw in the updateDynamicRules function within contentscript.js. This vulnerability allows attackers to exploit the argument yt-anti-adblock-detected, which can lead to improper authorization. Remotely exploitable, this weakness poses a significant risk as it could be leveraged for malicious attacks. The vendor has been informed about this issue but has not responded.

Affected Version(s)

Adblock for Youtube Extension 7.2.0

Adblock for Youtube Extension 7.2.1

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-19986 - Proof of Concept

References

https://vuldb.com/vuln/391190
vdb-entrytechnical-description
https://vuldb.com/vuln/391190/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-19986
third-party-advisory

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

DRXYJ (VulDB User)
VulDB CNA Team
.