CVE-2026-109774 Invalid pointer, undefined behavior in the DOM: Notifications component
An invalid pointer issue in the DOM Notifications component allows attackers to cause undefined behavior, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-109774?
CVE-2026-109774 is a critical memory corruption vulnerability in Mozilla Firefox, published on 13 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Invalid pointer, undefined behavior in the DOM: Notifications component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.
Weakness: CWE-824
Which versions are affected by CVE-2026-109774?
How do I fix CVE-2026-109774?
Upgrade to a fixed version.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-109774 being exploited?
There is no known exploitation of CVE-2026-109774 in the wild and no public exploit code.
Sources
Also known as GHSA-qh34-w7pf-vgw9, UBUNTU-CVE-2026-109774.