CVE-2026-49140

Nanobot < 0.2.1 Denial of Service via Matrix Media Download Handler

Published Jun 1, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Nanobot
Nanobot nanobot
CPEs cpe:2.3:a:nanobot:nanobot:*:*:*:*:*:python:*:*
Vendors & Products Nanobot
Nanobot nanobot
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Hkuds
Hkuds nanobot
Vendors & Products Hkuds
Hkuds nanobot
Type Values Removed Values Added
Description 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.
Title Nanobot < 0.2.1 Denial of Service via Matrix Media Download Handler
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L'}

cvssV4_0

{'score': 5.3, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Nov 8, 2026, 2:04 PM
Reserved
May 27, 2026, 5:40 PM
Status
Deferred
Published
Jun 1, 2026, 9:16 PM
Modified
Jul 22, 2026, 8:10 AM