Auth bypass in Adblock For Youtube Extension
CVE-2026-19986
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L.
EPSS exploit prediction
EPSS: 0.004 (33.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Adblock For Youtube Extension — versions 7.2.0, 7.2.1
Weakness classification (CWE)
References
- github.com/xryj920/chrome_extensions/blob/main/AdBlock Ltd. Adblock for Youtube… (exploit, media-coverage)
- vuldb.com/cve/CVE-2026-19986 (third-party-advisory)
- vuldb.com/submit/873935 (third-party-advisory)
- vuldb.com/vuln/391190 (technical-description, vdb-entry)
- vuldb.com/vuln/391190/cti (signature, permissions-required)
Frequently asked questions
- What is CVE-2026-19986?
- CVE-2026-19986 is a medium-severity vulnerability in Adblock For Youtube Extension, classified under Incorrect Privilege Assignment. CVSS score: 5.4/10. Published 2026-08-17.
- How severe is CVE-2026-19986?
- Medium severity. CVSS v3 base score is 5.4 out of 10.