Buffer overflow in Rtklib
CVE-2026-56789
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.004 (34.0th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 34.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Rtklib
- Tomojitakasu Rtklib — versions 0
Weakness classification (CWE)
References
- github.com/tomojitakasu/RTKLIB/issues/796 (Exploit, technical-description, Third Party Advisory, exploit, Issue Tracking)
- www.vulncheck.com/advisories/rtklib-heap-buffer-overflow-and-stack-read-via-ove… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-56789?
- CVE-2026-56789 is a medium-severity vulnerability in Rtklib, classified under Heap-based Buffer Overflow. CVSS score: 6.5/10. Published 2026-06-25.
- How severe is CVE-2026-56789?
- Medium severity. CVSS v3 base score is 6.5 out of 10.