CVE-2026-64951: Velociraptor DoS triggered by Divide by Zero panic

Published on 2026-07-31 Vulnogram
CVSS · LOW · 3.5 ⁄10 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
Scoring scenario: GENERAL
attackVector: NETWORK
attackComplexity: LOW
privilegesRequired: LOW
userInteraction: REQUIRED
scope: UNCHANGED
confidentialityImpact: NONE
integrityImpact: NONE
availabilityImpact: LOW
Description

A rogue Velociraptor client can upload a malformed sparse file such that if the GUI attempts to expand the file, a panic occurs which may crash the server process.

The problem is a Divide by Zero bug in the ShouldPadFile() function.

Problem CWE-369 Divide by zero
Required configuration for exposure The attacker needs to obtain deployment credentials to be able to start a rogue client and upload a specially crafted sparse file.
To successfully crash the server the Velociraptor user needs to export the file using the "Expand Sparse Files" option. If the option is not used the crash is not triggered.
Workarounds Usually the server will restart after the crash. The user should then export the file without the "Expand Sparse Files" option. 
ProductAffected
Rapid7 Velociraptor on Linux
source repo
Default status is unaffected 		before 0.77.2
Credits
  • Tristan Madani (Talence Security)
    •
References