9.8
CRITICAL CVSS 3.1
CVE-2026-56786
RTKLIB 2.4.3 - Out-of-bounds Write in decode_type1033 via Crafted RTCM3 Message
Description

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.

INFO

Published Date :

June 25, 2026, 7:16 p.m.

Last Modified :

July 14, 2026, 10:17 p.m.

Remotely Exploit :

Yes !
Affected Products

The following products are affected by CVE-2026-56786 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Rtklib rtklib
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 134c704f-9b21-4f2e-91b3-4a467353bcc0
CVSS 3.1 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 CRITICAL [email protected]
CVSS 4.0 CRITICAL 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 CRITICAL [email protected]
Solution
Update RTKLIB to patch an out-of-bounds write vulnerability in decode_type1033.
  • Update RTKLIB to the latest version.
  • Apply the vendor-provided patch for decode_type1033.
  • Validate buffer lengths before writing data.
  • Sanitize input length counters.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-56786.

URL Resource
https://github.com/tomojitakasu/RTKLIB/issues/799 Exploit Issue Tracking Third Party Advisory
https://www.vulncheck.com/advisories/rtklib-out-of-bounds-write-in-decode-type1033-via-crafted-rtcm3-message Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-56786 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-56786 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-56786 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-56786 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    Jul. 14, 2026

    Action Type Old Value New Value
    Changed Affected [{'repo': 'https://github.com/tomojitakasu/RTKLIB', 'vendor': 'tomojitakasu', 'product': 'RTKLIB', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.4.3'}], 'defaultStatus': 'unaffected'}] [{'repo': 'https://github.com/tomojitakasu/RTKLIB', 'vendor': 'tomojitakasu', 'product': 'RTKLIB', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.4.3'}], 'packageURL': 'pkg:github/tomojitakasu/RTKLIB', 'defaultStatus': 'unaffected'}]
  • Initial Analysis by [email protected]

    Jun. 26, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:rtklib:rtklib:*:*:*:*:*:*:*:* versions up to (including) 2.4.3
    Added Reference Type VulnCheck: https://github.com/tomojitakasu/RTKLIB/issues/799 Types: Exploit, Issue Tracking, Third Party Advisory
    Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/rtklib-out-of-bounds-write-in-decode-type1033-via-crafted-rtcm3-message Types: Third Party Advisory
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Jun. 25, 2026

    Action Type Old Value New Value
    Added SSVC {'id': 'CVE-2026-56786', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-25T18:41:31.254908Z'}
  • New CVE Received by [email protected]

    Jun. 25, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://github.com/tomojitakasu/RTKLIB', 'vendor': 'tomojitakasu', 'product': 'RTKLIB', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '2.4.3'}], 'defaultStatus': 'unaffected'}]
    Added Description 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.
    Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-787
    Added Reference https://github.com/tomojitakasu/RTKLIB/issues/799
    Added Reference https://www.vulncheck.com/advisories/rtklib-out-of-bounds-write-in-decode-type1033-via-crafted-rtcm3-message
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.