CVE-2025-30403 Memory corruption in mvfst
A heap-buffer-overflow in the mvfst QUIC library allows attackers to execute code or cause denial of service via crafted messages.
- 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
- None listed
What is CVE-2025-30403?
CVE-2025-30403 is a high-severity memory corruption vulnerability in Facebook mvfst, published on 11 Jul 2025. 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
A heap-buffer-overflow vulnerability is possible in mvfst via a specially crafted message during a QUIC session. This issue affects mvfst versions prior to v2025.07.07.00.
Which versions are affected by CVE-2025-30403?
How do I fix CVE-2025-30403?
No fix has been published for CVE-2025-30403 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-30403 being exploited?
There is no known exploitation of CVE-2025-30403 in the wild and no public exploit code.
Sources
Also known as GHSA-j73w-7xx9-cq3x.