CVE-2026-49140 MEDIUM

CVE-2026-49140: Nanobot < 0.2.1 Denial of Service via Matrix Media Download Handler

Vendor Hkuds
Product nanobot
Weakness CWE-770 · Uncontrolled resource consumption
Published June 1, 2026
Last update June 2, 2026

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

What the vulnerability does

01Description

Nanobot prior to version 0.2.1 contains a denial of service vulnerability in the Matrix channel media download handler that allows authenticated room members to exhaust process memory and bandwidth by sending media events with missing or invalid size metadata. Attackers can send multiple concurrent Matrix media events with omitted or invalid declared sizes to trigger simultaneous large media downloads that fully materialize response bodies before post-download rejection, consuming process resources until service degradation occurs.

Key dates

02Disclosure timeline

June 1, 2026 CVE published
June 2, 2026 Record updated