CVE-2024-56328Network attack vector

Arbitrary JavaScript execution via crafted Onebox URL

Published Feb 4, 2025 · Updated Feb 12, 2025

Stored cross-site scripting in Discourse stable 3.3.3 and earlier allows remote attackers to execute JavaScript in users' browsers. Discourse has not published the precise Onebox code path or faulty neutralization operation; beta and tests-passed 3.4.0.beta3 and earlier are also affected. A crafted Onebox URL must be posted and CSP must be disabled; execution is confined to browsers that render the malicious preview.

CVSS severity6.5
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Stored cross-site scripting in Discourse stable 3.3.3 and earlier allows remote attackers to execute JavaScript in users' browsers. Discourse has not published the precise Onebox code path or faulty neutralization operation; beta and tests-passed 3.4.0.beta3 and earlier are also affected. A crafted Onebox URL must be posted and CSP must be disabled; execution is confined to browsers that render the malicious preview.

The record

CVE
CVE-2024-56328
Published
Feb 4, 2025
Updated
Feb 12, 2025
Vendor
Discourse
Product
Discourse
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 4, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 12, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=beta: <= 3.4.0.beta3
  2. Affected versionversion=stable: <= 3.3.3
  3. Affected versionversion=tests-passed: <= 3.4.0.beta3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Discourse · Discourseversion=beta: <= 3.4.0.beta3; version=stable: <= 3.3.3; version=tests-passed: <= 3.4.0.beta3

Published CVSS scores

6.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/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
Privilegesunauthenticated
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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo