CVE-2026-16365
A security flaw in the DOM Workers component allows for privilege escalation. This means an attacker could potentially gain higher levels of access than intended within the application.
An official fix is available, so this entry is kept for 30 days and then removed automatically.
Who is affected
Users of Firefox and Thunderbird versions prior to 153.
Real-world impact
An attacker could exploit this flaw to gain unauthorized elevated permissions, potentially allowing them to perform actions or access data that should be restricted.
Why this severity
This vulnerability is rated critical because it can be exploited remotely over a network without requiring user interaction or any prior authentication, leading to a total loss of confidentiality, integrity, and availability.
What to do about it
- 011. Upgrade Firefox to version 153 or later.
- 022. Upgrade Thunderbird to version 153 or later.
NVD-referenced vendor advisory
Timeline
- Jul 21, 2026 · 12d agoPublishedDisclosed and added to the National Vulnerability Database.
- Jul 23, 2026 · 10d agoOfficial fix availableA vendor patch or mitigation now exists — see the remediation steps above.
- Jul 24, 2026 · 9d agoAdvisory updatedThe NVD record was last revised.
How it’s attacked
References & advisories
- bugzilla.mozilla.org/show_bug.cgipermissions required
- mozilla.org/security/advisories/mfsa202…vendor advisory
- mozilla.org/security/advisories/mfsa202…vendor advisory