Mozilla Firefox And Thunderbird Use-After-Free Vulnerability
Mozilla · Firefox and Thunderbird
CVSS 8.1
EPSS 6%
no public exploit indexed
Fix deadline passed 3 May 2022
What it is
Mozilla Firefox and Thunderbird contain a race condition vulnerability when handling a ReadableStream under certain conditions. The race condition creates a use-after-free vulnerability, causing unspecified impacts.
Why we say that
- CISA's federal remediation deadline (2022-05-03) has passed
- Listed in the CISA Known Exploited Vulnerabilities catalogue
Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.
What to do
Apply updates per vendor instructions.
What it costs when this goes wrong
This is where UK enforcement meets the vulnerability record. Where an unfixed vulnerability leads to a breach, the ICO treats it as a security failure under UK GDPR. Recent cases:
- The Electoral Commission Reprimand issued to the Electoral Commission in respect of Articles 5(1)(f) and 32(1)(b). Between 24 August 2021 and 27 October 20…
- Gain Capital UK Limited Gain Capital UK have been issued a Reprimand in respect of Articles 32 (2) and 32 (1) (b). An unauthorised third party leveraged a…
- Chartered Institute for Securities & Investment An unauthorised third party exploited a known vulnerability in the Sitefinity software to leverage a bruteforce attack to upload a…