Out-of-Bounds Write Vulnerability in RTKLIB by Tomoji Takasu
CVE-2026-56786

9.3CRITICAL

Key Information:

Vendor

Tomojitakasu

Status
Rtklib
Vendor
CVE Published:
25 June 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-56786?

RTKLIB versions up to 2.4.3 are affected by an out-of-bounds write vulnerability in the decode_type1033 function. This flaw arises from the failure to properly clamp length counters to the destination buffer size, allowing attackers to exploit it via crafted RTCM3 messages. By manipulating the NTRIP or serial correction stream, an attacker can trigger up to a 191-byte overflow into fixed 64-byte descriptor fields. This vulnerability can lead to corruption of adjacent rtcm_t object members, potentially enabling arbitrary code execution or causing denial of service.

Affected Version(s)

RTKLIB 0 <= 2.4.3

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-56786 - Proof of Concept

References

https://github.com/tomojitakasu/RTKLIB/issues/799
technical-descriptionexploit
https://www.vulncheck.com/advisories/rtklib-out-of-bounds...
third-party-advisory

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

FuzzingLabs
.