Vulnerability · Published Jul 21, 2026 · Assigned by mozilla
CVE-2026-16404Spoofing issue in Firefox for Android
High 7.4
In plain English
A high-severity authentication bypass by spoofing in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities).
Severity (CVSS 3.1)7.4High
Exploit odds (30 days)0.3%top 80.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Spoofing issue in Firefox for Android. This vulnerability was fixed in Firefox 153.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-16404 |
| Ubuntu:24.04:LTS | mozjs102 | no fix listed | UBUNTU-CVE-2026-16404 |
| Ubuntu:24.04:LTS | mozjs115 | no fix listed | UBUNTU-CVE-2026-16404 |
| Ubuntu:22.04:LTS | mozjs78 | no fix listed | UBUNTU-CVE-2026-16404 |
| Ubuntu:22.04:LTS | mozjs91 | no fix listed | UBUNTU-CVE-2026-16404 |
| Ubuntu:22.04:LTS | thunderbird | no fix listed | UBUNTU-CVE-2026-16404 |
Affected products (as reported)
Weakness: CWE-290 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:H/A:N