CVE-2023-22455Network attack vector

Cross-site scripting via unescaped tag descriptions

Published Jan 5, 2023 · Updated Mar 10, 2025

Cross-site scripting in Discourse before 2.8.14 and 2.9.0.beta0 through 3.0.0.beta15 allows remote authenticated users to run scripts. The tag renderer inserts moderator-controlled description text into an HTML title attribute without escaping quotes, allowing attribute breakout. Moderator privileges and a modified or disabled default Content Security Policy are required for full script execution in visitors' browsers.

CVSS severity6.8
Medium
EPSS probability0.48%
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 before 2.8.14 and 2.9.0.beta0 through 3.0.0.beta15 allows remote authenticated users to run scripts. The tag renderer inserts moderator-controlled description text into an HTML title attribute without escaping quotes, allowing attribute breakout. Moderator privileges and a modified or disabled default Content Security Policy are required for full script execution in visitors' browsers.

The record

CVE
CVE-2023-22455
Published
Jan 5, 2023
Updated
Mar 10, 2025
Vendor
Discourse
Product
Discourse
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 5, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 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=< 2.8.14
  2. Affected versionversion=>= 2.9.0.beta0, < 3.0.0.beta16

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Discourse · Discourseversion=< 2.8.14; version=>= 2.9.0.beta0, < 3.0.0.beta16

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
6.8GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript

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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