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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-42859 Detail

Description

Neat VNC is a VNC server library. Prior to 0.9.6, a pre-authentication stack buffer overflow exists in neatvnc in the RSA-AES security type handler. An unauthenticated remote attacker who can reach the VNC listening socket can send a crafted security type 5 (RSA-AES) or security type 129 (RSA-AES-256) handshake with an oversized client RSA public key, causing rsa_aes_send_challenge in src/auth/rsa-aes.c to overflow a 1024-byte on-stack buffer when encrypting the server challenge. This results in at least a denial of service via server crash. This vulnerability is fixed in 0.9.6.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
CVSS-BT 8.1 HIGH
Vector:  CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://github.com/any1/neatvnc/commit/1f6cd6b75cc167fed3a19a9d1552a1f662f6b337 GitHub, Inc.
https://github.com/any1/neatvnc/security/advisories/GHSA-567c-gpv8-qh9h GitHub, Inc.

Weakness Enumeration

CWE-ID CWE Name Source
CWE-120 Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') GitHub, Inc.  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-42859
NVD Published Date:
05/11/2026
NVD Last Modified:
05/11/2026
Source:
GitHub, Inc.