CVE-2026-16409 Invalid pointer in the Security: PSM component
An invalid pointer in the PSM component can cause a crash, requiring users to upgrade Firefox and Thunderbird.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-16409?
CVE-2026-16409 is a high-severity vulnerability in Mozilla Firefox, published on 21 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Invalid pointer in the Security: PSM component. This vulnerability was fixed in Firefox 153 and Thunderbird 153.
Weakness: CWE-824
Which versions are affected by CVE-2026-16409?
It affects 2 products.
Products include Mozilla Firefox, Mozilla Thunderbird.
How do I fix CVE-2026-16409?
Upgrade to a fixed version.
Is CVE-2026-16409 being exploited?
There is no known exploitation of CVE-2026-16409 in the wild and no public exploit code.
Other vulnerabilities in Mozilla Firefox
Sources
Also known as GHSA-gcmc-83gc-jhq6, UBUNTU-CVE-2026-16409.