Junglewise Threat Intelligence

CVE-2026-56789: RTKLIB heap buffer overflow in readrnxobsb function

CVE-2026-56789 · Severity: medium · CVSS 6.5 · Published 2026-06-25

Technologies: Tomoji Takasu RTKLIB. Vendors: Tomoji Takasu.

Executive brief

RTKLIB is an open-source program package for standard and precise positioning with GNSS (Global Navigation Satellite System). A vulnerability in how it processes satellite data files could allow an attacker to crash applications using this library, such as rnx2rtkp and RTKPOST, by providing a specially crafted file. This could lead to a denial of service, interrupting precise positioning and navigation operations.

Technical details

A heap-based buffer overflow exists in RTKLIB versions up to and including 2.4.3 within the readrnxobsb function in src/rinex.c. The vulnerability is caused by a failure to properly validate or 'clamp' the satellite count values provided in RINEX epoch headers. By crafting a RINEX file that declares more than 64 satellites per epoch, an attacker can trigger heap buffer overflow writes and out-of-bounds stack reads. This typically results in a crash (Denial of Service) of applications linked against the library, such as rnx2rtkp and RTKPOST. Exploitation requires the victim to open or process a malicious RINEX file.

Affected products

  • tomojitakasu RTKLIB through 2.4.3

Timeline

  • 2026-06-25: disclosed
  • 2026-06-25: advisory

References

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