CVE-2026-7686

MEDIUM

eyeo Adblock Plus Legacy Premium Activation premium.preload.js postMessage access control

Title source: cna
STIX 2.1

Description

A vulnerability was found in eyeo Adblock Plus up to 4.36.2 on Chrome. Affected by this vulnerability is the function postMessage of the file premium.preload.js of the component Legacy Premium Activation. Performing a manipulation results in improper access controls. Remote exploitation of the attack is possible. The exploit has been made public and could be used. Upgrading the affected component is recommended. The vendor provides additional details: "The affected code path is a legacy Premium activation flow that has been deprecated. eyeo has already migrated to a new user account-based licensing system. The exploit does not grant permanent Premium access. The licensing server issues a short-lived trial license (valid for approximately 24 hours) for any submitted userId. On the next license check, the server validates against a real subscription and the trial expires if no valid subscription is found. The researcher's claim of permanently unlocking all Premium features is therefore incorrect. (...) The old flow has been present for years and has not been weaponized at scale to our knowledge. The risk to eyeo and to users is minimal."

References (5)

Core 5
Core References
Vdb Entry, Technical Description vdb-entry technical-description
VDB-360856 | eyeo Adblock Plus Legacy Premium Activation premium.preload.js postMessage access control
https://vuldb.com/vuln/360856
Signature, Permissions Required signature permissions-required
VDB-360856 | CTI Indicators (IOB, IOC, TTP, IOA)
https://vuldb.com/vuln/360856/cti
Third Party Advisory third-party-advisory
Submit #793551 | Eyeo GmbH Adblock Plus 4.36.2 Privilege Escalation
https://vuldb.com/submit/793551

Scores

CVSS v3 5.3
EPSS 0.0003
EPSS Percentile 8.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CISA SSVC

Vulnrichment
Exploitation poc
Automatable yes
Technical Impact partial

Details

CWE
CWE-266 CWE-284
Status published
Products (3)
eyeo/Adblock Plus 4.36.0
eyeo/Adblock Plus 4.36.1
eyeo/Adblock Plus 4.36.2
Published May 03, 2026
Tracked Since May 03, 2026