PT-2026-45562 · Hkuds · Nanobot

Published 2026-06-01 · Updated 2026-06-01 · CVE-2026-49140

Mitre

CVSS v3.1

4.3

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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.

Fix

Allocation of Resources Without Limits

Weakness Enumeration

CWE-770

Related Identifiers

CVE-2026-49140

Affected Products

Nanobot

References · 5

• https://github.com/HKUDS/nanobot/commit/1d4000560dfff1acb83f5c5ca8ef3ab1f092bd14 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-49140 · Security Note
• https://github.com/HKUDS/nanobot/pull/4106 · Note
• https://github.com/HKUDS/nanobot/releases/tag/v0.2.1 · Note
• https://vulncheck.com/advisories/nanobot-denial-of-service-via-matrix-media-download-handler · Note