If the ALT and "a" keys are pressed when users receive an extension installation prompt, the extension will be installed without the instal…

published 2019-07-23 7 y ago modified 2026-06-17 4 mo ago also EUVD-2019-3367

cvss: 6.5; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.8%; EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits: 0; none known

If the ALT and "a" keys are pressed when users receive an extension installation prompt, the extension will be installed without the install prompt delay that keeps the prompt visible in order for users to accept or decline the installation. A malicious web page could use this with spoofing on the page to trick users into installing a malicious extension. This vulnerability affects Firefox < 67.

Patch / fix

fixed in 1 distros 3

Mozilla Firefox 67

ubuntu opensuse arch linux

firefox Ubuntu 16.04 LTS 67.0+build2-0ubuntu0.16.04.1
firefox Ubuntu 18.04 LTS 67.0+build2-0ubuntu0.18.04.1

ubuntu advisories UBUNTU-CVE-2019-11697

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

firefox-esr openSUSE Tumbleweed 128.5.1-1.1
MozillaFirefox openSUSE Tumbleweed 92.0-1.2

opensuse advisories openSUSE-SU-2024:14572-1 openSUSE-SU-2024:10600-1

firefox Arch Linux 67.0-1

arch linux advisories AVG-966

Exploit prediction

0.85% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:P/A:N

Affected products

Mozilla Firefox

Classification

Weakness

CWE-20 Improper Input Validation

References

mozilla.org /security/advisories/mfsa2019-13/
vendor-advisory
bugzilla.mozilla.org /show_bug.cgi?id=1440079
issue-tracking, permissions-required, vendor-advisory

Sources

CVE List CVE-2019-11697
NVD CVE-2019-11697

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary