CVE-2026-49140

MEDIUM SEVERITY

CVSS Score & Metrics

Base Score

4.3 / 10

Vector String

                                        CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L                                    

Vulnerability 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.

Vulnerability Details

Published Date

June 01, 2026

Last Modified

June 02, 2026

CWE ID

CWE-770

Source

NVD

Vendor

HKUDS

Product

nanobot

External References

https://github.com/HKUDS/nanobot/commit/1d4000560dfff1acb83f5c5ca8ef3ab1f092bd14
https://github.com/HKUDS/nanobot/pull/4106
https://github.com/HKUDS/nanobot/releases/tag/v0.2.1
https://www.vulncheck.com/advisories/nanobot-denial-of-service-via-matrix-media-download-handler

CVE-2026-49140

CVSS Score & Metrics

Vulnerability Description

Vulnerability Details

External References

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