CVE-2026-19986Public exploitNetwork attack vector

Persistent ad-block disablement via DOM event

Published Aug 17, 2026 · Updated Aug 19, 2026

Improper authorization in Adblock for Youtube 7.2.0 through 7.2.1 allows attackers to disable ad blocking via a DOM event. The contentscript.js listener treats the hard-coded yt-anti-adblock-detected window event as authority, writes ads=false into chrome.storage.local, and triggers updateDynamicRules to remove Declarative Net Request rules without validating the event source. Exploitation requires script execution in a YouTube page, or a co-installed extension with YouTube access, and leaves the extension persistently disabled until the setting is changed again.

CVSS severity5.4
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authorization in Adblock for Youtube 7.2.0 through 7.2.1 allows attackers to disable ad blocking via a DOM event. The contentscript.js listener treats the hard-coded yt-anti-adblock-detected window event as authority, writes ads=false into chrome.storage.local, and triggers updateDynamicRules to remove Declarative Net Request rules without validating the event source. Exploitation requires script execution in a YouTube page, or a co-installed extension with YouTube access, and leaves the extension persistently disabled until the setting is changed again.

The record

CVE
CVE-2026-19986
Published
Aug 17, 2026
Updated
Aug 19, 2026
Vendor
AdBlock Ltd.
Product
Adblock for Youtube
Classifications
CWE-285, CWE-266, T1562.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=7.2.0
  2. Affected versionversion=7.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

AdBlock Ltd. · Adblock for Youtubeversion=7.2.0; version=7.2.1

Published CVSS scores

5.4VulDBCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
2.1VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
6.4VulDBAV:N/AC:L/Au:N/C:N/I:P/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-285Improper Authorization
CWE-266Incorrect Privilege Assignment
T1562.001Impair Defenses: Disable or Modify Tools

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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