CVE-2026-16361 Memory safety bugs fixed in Thunderbird ESR 140.13
Memory safety bugs in Thunderbird could allow arbitrary code execution, requiring users to upgrade to the latest version.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-16361?
CVE-2026-16361 is a critical memory corruption 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
Memory safety bugs present in Thunderbird ESR 140.12. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability was fixed in Firefox ESR 115.38, Firefox ESR 140.13, and Thunderbird 140.13.
Weakness: CWE-119
Which versions are affected by CVE-2026-16361?
It affects 2 products.
Products include Mozilla Firefox, Mozilla Thunderbird.
How do I fix CVE-2026-16361?
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-2026-16361 being exploited?
There is no known exploitation of CVE-2026-16361 in the wild and no public exploit code.
Other vulnerabilities in Mozilla Firefox
Sources
Also known as DEBIAN-CVE-2026-16361, GHSA-vmm5-fq3q-c8fc.