CVE-2026-56786 RTKLIB 2.4.3 - Out-of-bounds Write in decode_type1033 via Crafted RTCM3 Message
An attacker can achieve arbitrary code execution or denial of service by sending a crafted RTCM3 message to RTKLIB due to an out-of-bounds write.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-56786?
CVE-2026-56786 is a critical memory corruption vulnerability in tomojitakasu RTKLIB, published on 25 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
RTKLIB through 2.4.3 contains an out-of-bounds write vulnerability in decode_type1033 function that fails to clamp length counters to destination buffer size, allowing up to 191-byte overflow into fixed 64-byte descriptor fields. An attacker controlling an NTRIP or serial RTCM3 correction stream can craft a valid CRC-bearing type-1033 message to corrupt adjacent rtcm_t object members, potentially achieving arbitrary code execution or denial of service.
Weakness: CWE-787
Which versions are affected by CVE-2026-56786?
It affects 1 product.
Products include Rtklib Rtklib.
How do I fix CVE-2026-56786?
No fix has been published for CVE-2026-56786 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-2026-56786 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56786 exists.
Other vulnerabilities in tomojitakasu RTKLIB
Sources
Also known as DEBIAN-CVE-2026-56786, GHSA-5cx9-6hw2-hchv, UBUNTU-CVE-2026-56786.