CVE-2026-49140

Nanobot < 0.2.1 Denial of Service via Matrix Media Download Handler

MEDIUM
4.3
CVSS Score
Published: June 1, 2026 at 07:54 PM UTC
Updated: July 22, 2026 at 08:27 AM UTC
2 products affected across 2 vendorsNanobotNanobot

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Severity
MEDIUM4.3
Exploit prediction
EPSS 0.3%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.2.1
Affected range stops below 0.2.1, so it looks safe — our inference, not a vendor statement
v < 0.2.1
Affected range stops below 0.2.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.3MEDIUMVulnCheck
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-770

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