Buffer overflow in Rtklib
CVE-2026-56786
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (51.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
- Rtklib
- Tomojitakasu Rtklib — versions 0
Weakness classification (CWE)
References
- github.com/tomojitakasu/RTKLIB/issues/799 (Exploit, technical-description, Third Party Advisory, exploit, Issue Tracking)
- www.vulncheck.com/advisories/rtklib-out-of-bounds-write-in-decode-type1033-via-… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-56786?
- CVE-2026-56786 is a critical-severity vulnerability in Rtklib, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2026-06-25.
- How severe is CVE-2026-56786?
- Critical severity. CVSS v3 base score is 9.8 out of 10.