Summary
matrix-react-sdk vulnerable to XSS in Export Chat feature
Description
The Export Chat feature includes certain attacker-controlled elements in the generated document without sufficient escaping, leading to stored XSS.
Workarounds
None, other than not using the Export Chat feature.
References
N/A
Impact
Since the Export Chat feature generates a separate document, an attacker can only inject code run from the null origin, restricting the impact.
However, the attacker can still potentially use the XSS to leak message contents. A malicious homeserver is a potential attacker since the affected inputs are controllable server-side.
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
CVE-2023-37259 has a CVSS score of 6.1 (Medium). The vector is reachable from an adjacent network, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.76.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
This was patched in matrix-react-sdk 3.76.0.
Frequently Asked Questions
- What is CVE-2023-37259? CVE-2023-37259 is a medium-severity cross-site scripting (XSS) vulnerability in matrix-react-sdk (npm), affecting versions >= 3.32.0, < 3.76.0. It is fixed in 3.76.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2023-37259? CVE-2023-37259 has a CVSS score of 6.1 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of matrix-react-sdk are affected by CVE-2023-37259? matrix-react-sdk (npm) versions >= 3.32.0, < 3.76.0 is affected.
- Is there a fix for CVE-2023-37259? Yes. CVE-2023-37259 is fixed in 3.76.0. Upgrade to this version or later.
- Is CVE-2023-37259 exploitable, and should I be worried? Whether CVE-2023-37259 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-37259 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-37259? Upgrade
matrix-react-sdkto 3.76.0 or later.