CVE-2026-19986 Adblock for Youtube Extension Event Listener contentscript.js updateDynamicRules improper authorization
Attackers can bypass authorization checks in the Adblock for Youtube extension to manipulate ad-blocking rules remotely.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-19986?
CVE-2026-19986 is a medium-severity missing authorization vulnerability in Adblock for Youtube Extension, published on 17 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
A weakness has been identified in Adblock for Youtube Extension up to 7.2.1 on Chrome. The impacted element is the function updateDynamicRules of the file contentscript.js of the component Event Listener. This manipulation of the argument yt-anti-adblock-detected causes improper authorization. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-19986?
How do I fix CVE-2026-19986?
No fix has been published for CVE-2026-19986 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-19986 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-19986 exists.
Sources
Also known as GHSA-9h57-f8p2-fmg7.