Off-by-One Buffer Overflow in CANBoat Allows Remote Denial of Service
CVE-2026-56790

7HIGH

Key Information:

Vendor

Canboat

Status
Canboat
Vendor
CVE Published:
25 June 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-56790?

The CANBoat application prior to version 6.22 is susceptible to an off-by-one global buffer overflow vulnerability within the searchForPgn() function, located in analyzer/pgn.c. This flaw may be exploited by remote attackers who deliver specially crafted NMEA-2000 messages containing out-of-range PGN values over a CAN bus or N2K-over-IP connection. Successful exploitation can lead to an out-of-bounds array access, causing the application to crash and resulting in a denial of service.

Affected Version(s)

canboat 0 <= 6.22

canboat a5a22b74b9ac5688019cba62669df08562cebd6f

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-2026-56790 - Proof of Concept

References

https://github.com/canboat/canboat/issues/644
technical-descriptionexploit
https://github.com/canboat/canboat/pull/649
issue-tracking
https://github.com/canboat/canboat/commit/a5a22b74b9ac568...
patch

CVSS V4

Score:
7
Severity:
HIGH
Confidentiality:
Low
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

FuzzingLabs
.