CVE-2026-19986
Adblock for Youtube Extension Event Listener contentscript.js updateDynamicRules improper authorization
- 5.3MediumCVSS base score
- 0.42%Exploitation in 30 daysEPSS · top 63% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. 2 references of the record are tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits2
References tagged exploit2 references
- Submit #873935 | AdBlock Ltd. Adblock for Youtube Chrome extension 7.2.1 Improper validation of event origin / authenticity (opens in a new tab)third-party-advisoryexploit
- https://github.com/xryj920/chrome_extensions/blob/main/AdBlock%20Ltd.%20Adblock%20for%20Youtube%207.2.1%20allows%20persistent%20disabling%20of%20ad%20blocking%20through%20an%20unauthenticated%20DOM%20event (opens in a new tab)exploitmedia-coverage
Timeline
ID reserved
By VulDB
- 1 day later
· 1 day later
Published
- 2 days later
· 2 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| VulDBCNA (assigner) | 4.0 | Medium5.3 | CVSS: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 |
| VulDBCNA (assigner) | 3.1 | Medium5.4 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L/E:P/RL:X/RC:R |
| VulDBCNA (assigner) | 3.0 | Medium5.4 | CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L/E:P/RL:X/RC:R |
| VulDBCNA (assigner) | 2.0 | Medium6.4 | AV:N/AC:L/Au:N/C:N/I:P/A:P/E:POC/RL:ND/RC:UR |
| NVDNVD · Deferred | 4.0 | Low2.1 | CVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
- EPSS (exploitation in 30 days)
- 0.42% · top 63% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
Adblock for Youtube Extension
- affected 7.2.0
- affected 7.2.1
References
References5
- VDB-391190 | Adblock for Youtube Extension Event Listener contentscript.js updateDynamicRules improper authorization (opens in a new tab)vdb-entrytechnical-description
- VDB-391190 | CTI Indicators (IOB, IOC, TTP, IOA) (opens in a new tab)signaturepermissions-required
- CVE-2026-19986 | CVE Analysis and Report (opens in a new tab)third-party-advisory
- Submit #873935 | AdBlock Ltd. Adblock for Youtube Chrome extension 7.2.1 Improper validation of event origin / authenticity (opens in a new tab)third-party-advisoryexploit
- https://github.com/xryj920/chrome_extensions/blob/main/AdBlock%20Ltd.%20Adblock%20for%20Youtube%207.2.1%20allows%20persistent%20disabling%20of%20ad%20blocking%20through%20an%20unauthenticated%20DOM%20event (opens in a new tab)exploitmedia-coverage
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-60048 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-19986)Record last updated .