CVE-2026-88830 Busybox: busybox: tls montgomery reduction allocates bytes instead of digits, causing a pre-auth heap buffer overflow
A heap buffer overflow in BusyBox TLS implementation allows remote 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
- Not needed
- Fix
- Available
What is CVE-2026-88830?
CVE-2026-88830 is a high-severity memory corruption vulnerability in Red Hat Hardened Images, published on 23 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A unit confusion in BusyBox TLS Montgomery reduction buffer allocation causes a pre-authentication heap buffer overflow when processing a crafted ClientKeyExchange message.
Weakness: CWE-131
Which versions are affected by CVE-2026-88830?
How do I fix CVE-2026-88830?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-88830 being exploited?
There is no known exploitation of CVE-2026-88830 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-88830, ECHO-cdc3-3b65-f4a0, GHSA-mv57-fr8w-22gj, UBUNTU-CVE-2026-88830.