CVE-2026-56789: Rtklib

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

RTKLIB through 2.4.3 contains a heap buffer overflow vulnerability in the readrnxobsb function in src/rinex.c that allows attackers to trigger memory corruption by failing to clamp satellite count values from RINEX epoch headers. Attackers can craft malicious RINEX files declaring more than 64 satellites per epoch to cause heap buffer overflow writes and out-of-bounds stack reads, crashing RTKLIB-based applications including rnx2rtkp and RTKPOST.

Affected products

• Rtklib Rtklib: up to and including 2.4.3

Published 2026-06-25. Last modified 2026-07-14.