CVE-2018-12396

critical
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
9.5

Description

A vulnerability where a WebExtension can run content scripts in disallowed contexts following navigation or other events. This allows for potential privilege escalation by the WebExtension on sites where content scripts should not be run. This vulnerability affects Firefox ESR < 60.3 and Firefox < 63.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2018-12396

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2018-12396.html

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-201810-14

OS impact

OSVersionStatusFixed in
arch archfixed63.0-1
suse slesaffected
debian debiansidfixed63.0-1
debian debianbookwormfixed60.3.0esr-1
debian debianbullseyefixed60.3.0esr-1
debian debianforkyfixed60.3.0esr-1
debian debiantrixiefixed60.3.0esr-1

References

Verify integrity in audit chain (admin only). AS-IS.