CVE-2018-12399

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

Description

When a new protocol handler is registered, the API accepts a title argument which can be used to mislead users about which domain is registering the new protocol. This may result in the user approving a protocol handler that they otherwise would not have. This vulnerability affects 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-2018-12399

vendor Authored 2026-05-27

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

OS impact

OSVersionStatusFixed in
arch archfixed63.0-1
debian debiansidfixed63.0-1

References

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