CVE-2025-58054Network attack vector

Script execution via unsanitized quoted chat titles

Published Oct 1, 2025 · Updated Oct 1, 2025

Cross-site scripting in Discourse 3.5.0 and earlier allows remote authenticated users to run script via quoted chat titles. The chat rich-editor extension passes channel and thread title attributes through emojiUnescape and assigns the result to innerHTML without HTML sanitization. Exploitation requires a low-privilege user to create a crafted title, another user to quote it in the rich text editor, and CSP to be disabled, exposing data accessible to that user's browser.

CVSS severity3.5
Low
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Discourse 3.5.0 and earlier allows remote authenticated users to run script via quoted chat titles. The chat rich-editor extension passes channel and thread title attributes through emojiUnescape and assigns the result to innerHTML without HTML sanitization. Exploitation requires a low-privilege user to create a crafted title, another user to quote it in the rich text editor, and CSP to be disabled, exposing data accessible to that user's browser.

The record

CVE
CVE-2025-58054
Published
Oct 1, 2025
Updated
Oct 1, 2025
Vendor
Discourse
Product
Discourse
Classifications
CWE-80, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 1, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 1, 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=< 3.5.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Discourse · Discourseversion=< 3.5.1

Published CVSS scores

3.5GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-80Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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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