CVE-2026-7686: 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....

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."

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

CVSS 4.0

5.5/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/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 Probability

0.30%

21.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

References

Timeline

Published: May 3, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-7686?

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."

How severe is CVE-2026-7686?

CVE-2026-7686 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.30% probability of exploitation in the next 30 days.

How do I fix CVE-2026-7686?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.