CVE-2026-49140
Nanobot < 0.2.1 Denial of Service via Matrix Media Download Handler
CVSS Score
4.3
EPSS Score
0.0%
EPSS Percentile
12th
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.
| CWE | CWE-770 |
| Vendor | hkuds |
| Product | nanobot |
| Published | Jun 1, 2026 |
| Last Updated | Jun 2, 2026 |
Stay Ahead of the Next One
Get instant alerts for hkuds nanobot
Be the first to know when new medium vulnerabilities affecting hkuds nanobot are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
Low
Affected Versions
HKUDS / nanobot
0 < 0.2.1
References
github.com: https://github.com/HKUDS/nanobot/releases/tag/v0.2.1 github.com: https://github.com/HKUDS/nanobot/pull/4106 github.com: https://github.com/HKUDS/nanobot/commit/1d4000560dfff1acb83f5c5ca8ef3ab1f092bd14 vulncheck.com: https://www.vulncheck.com/advisories/nanobot-denial-of-service-via-matrix-media-download-handler
Credits
Chia Min Jun Lennon