CVE-2023-37259

Chat message disclosure via unescaped export metadata

Published Jul 18, 2023 · Updated Oct 18, 2024

Stored XSS in Matrix.org matrix-react-sdk 3.32.0 through 3.75.x allows attackers to read exported chat messages through crafted room metadata. HTMLExporter interpolates the room name and topic into generated HTML without escaping them, so markup in Matrix room state becomes executable script. Exploitation requires a user to export and open the chat; the script runs from a null origin but can read message contents in the exported document.

CVSS severity6.1
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Matrix.org matrix-react-sdk 3.32.0 through 3.75.x allows attackers to read exported chat messages through crafted room metadata. HTMLExporter interpolates the room name and topic into generated HTML without escaping them, so markup in Matrix room state becomes executable script. Exploitation requires a user to export and open the chat; the script runs from a null origin but can read message contents in the exported document.

The record

CVE
CVE-2023-37259
Published
Jul 18, 2023
Updated
Oct 18, 2024
Vendor
Matrix.org
Product
matrix-react-sdk
Classifications
CWE-79, T1203
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Jul 18, 2023CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 2024Record 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=>= 3.32.0, < 3.76.0

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

Matrix.org · matrix-react-sdkversion=>= 3.32.0, < 3.76.0

Published CVSS scores

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
6.1GitHub, Inc.CVSS:3.1/AV:A/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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