Vulnerability · Published Jun 25, 2026 · Assigned by VulnCheck
CVE-2026-56789RTKLIB 2.4.3 - Heap Buffer Overflow and Stack Read via Oversized RINEX Epoch Satellite Count
Medium 6.5
In plain English
A medium-severity heap buffer overflow in RTKLIB from tomojitakasu. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities).
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | rtklib | no fix listed | DEBIAN-CVE-2026-56789 |
| Debian:13 | rtklib | no fix listed | DEBIAN-CVE-2026-56789 |
| Debian:14 | rtklib | no fix listed | DEBIAN-CVE-2026-56789 |
| Ubuntu:22.04:LTS | rtklib | no fix listed | UBUNTU-CVE-2026-56789 |
| Ubuntu:24.04:LTS | rtklib | no fix listed | UBUNTU-CVE-2026-56789 |
| Ubuntu:25.10 | rtklib | no fix listed | UBUNTU-CVE-2026-56789 |
| Ubuntu:26.04:LTS | rtklib | no fix listed | UBUNTU-CVE-2026-56789 |
| Ubuntu:26.10 | rtklib | no fix listed | UBUNTU-CVE-2026-56789 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| tomojitakasu | RTKLIB | 0 – through 2.4.3 |
Weakness: CWE-122 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
References
- Researcher Disclosure technical-description, exploit
- https://www.vulncheck.com/advisories/rtklib-heap-buffer-overflow-and-stack-read-via-oversized-rinex-epoch-satellite-count third-party-advisory