CVE-2025-49090Network attack vector

Room-state corruption via deficient state resolution

Published Oct 2, 2025 · Updated Oct 2, 2025

State resolution in The Matrix.org Foundation Matrix Specification before 1.16 allows remote authenticated users to corrupt room state. State Resolution 2.0 produces an earlier or incorrect room state for crafted edge-case sequences of Matrix events and API responses, even without valid revocation events. Exploitation requires control of a homeserver participating in the affected room and can reset or overwrite security-relevant room state.

CVSS severity7.1
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

State resolution in The Matrix.org Foundation Matrix Specification before 1.16 allows remote authenticated users to corrupt room state. State Resolution 2.0 produces an earlier or incorrect room state for crafted edge-case sequences of Matrix events and API responses, even without valid revocation events. Exploitation requires control of a homeserver participating in the affected room and can reset or overwrite security-relevant room state.

The record

CVE
CVE-2025-49090
Published
Oct 2, 2025
Updated
Oct 2, 2025
Vendor
The Matrix.org Foundation
Product
Matrix Specification
Classifications
CWE-642, CAPEC-31, CAPEC-21, T1565
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 2, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 2, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.16

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

The Matrix.org Foundation · Matrix Specificationversion=0 <1.16

Published CVSS scores

7.1MITRECVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-642External Control of Critical State Data
CAPEC-31Accessing/Intercepting/Modifying HTTP Cookies
CAPEC-21Exploitation of Trusted Identifiers
T1565Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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