Is CVE-2026-56787 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-56787 being exploited in the wild.

How severe is CVE-2026-56787?

Medium severity, with a CVSS score of 6.5, published 25 June 2026.

Which products and versions are affected?

Tomoji Takasu RTKLIB through 2.4.3.

Is there a fix for CVE-2026-56787?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-56787 attacked?

It is attacked over the network, in a software library.

Am I affected by CVE-2026-56787?

Check whether you run Tomoji Takasu RTKLIB at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-56787: RTKLIB off-by-one error in decode_ssr3 function

CVE-2026-56787 · Severity: medium · CVSS 6.5 · Published 2026-06-25

RTKLIB is an open-source library used for high-precision satellite positioning in GPS/GNSS receivers and base stations. A vulnerability in how the software processes correction data allows a remote attacker to send a specially crafted message that can crash the system. This could lead to a loss of positioning services for mobile rovers or the failure of permanent reference stations (CORS) used in surveying and navigation.

Technologies: Tomoji Takasu RTKLIB. Vendors: Tomoji Takasu.

Quick answers

Is CVE-2026-56787 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-56787 being exploited in the wild.
How severe is CVE-2026-56787?: Medium severity, with a CVSS score of 6.5, published 25 June 2026.
Which products and versions are affected?: Tomoji Takasu RTKLIB through 2.4.3.
Is there a fix for CVE-2026-56787?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-56787 attacked?: It is attacked over the network, in a software library.
Am I affected by CVE-2026-56787?: Check whether you run Tomoji Takasu RTKLIB at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

An off-by-one error exists in the `decode_ssr3` function within `src/rtcm3.c` at line 1446. The vulnerability is triggered when processing RTCM3 State Space Representation (SSR) messages containing attacker-controlled signal mode fields. By sending a crafted SSR correction stream via NTRIP or serial connections, a remote attacker can cause an out-of-bounds read leading to a global buffer overflow. This results in a denial-of-service (DoS) condition, crashing RTKLIB-based rovers or CORS servers. As of the advisory date, the issue affects all versions through 2.4.3.

Affected products

tomojitakasu RTKLIB through 2.4.3

Timeline

2026-06-09: disclosed: Issue reported on GitHub by researcher raefko (FuzzingLabs)
2026-06-25: advisory: NVD and VulnCheck published advisory details

References

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