WhatsApp for Windows <2.3000: File Ext Spoofing via NUL Bytes
CVE-2026-23863 Published on May 1, 2026
An attachment spoofing issue in WhatsApp for Windows prior to v2.3000.1032164386.258709 could have allowed maliciously formatted documents with embedded NUL bytes in the filename to be shown in the application as one type of file but run as an executable when opened. We have not seen evidence of exploitation in the wild.
Weakness Type
Improper Neutralization of Null Byte or NUL Character
The software receives input from an upstream component, but it does not neutralize or incorrectly neutralizes NUL characters or null bytes when they are sent to a downstream component. As data is parsed, an injected NUL character or null byte may cause the software to believe the input is terminated earlier than it actually is, or otherwise cause the input to be misinterpreted. This could then be used to inject potentially dangerous input that occurs after the null byte or otherwise bypass validation routines and other protection mechanisms.
Affected Versions
Facebook WhatsApp Desktop for Windows:- Version 2.3000.*.252500 and below 2.3000.1032164386.258709 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.