CVE-2025-48062Network attack vector

HTML injection via unescaped email topic titles

Published Jun 9, 2025 · Updated Jun 9, 2025

HTML injection in Discourse before 3.4.4, 3.5.0.beta5, or 3.5.0.beta6-dev allows remote authenticated users to alter invitation emails. The invite mailer inserts a topic title containing HTML into the invite_mailer template's {topic_title} field without neutralizing markup. An account able to create an HTML-bearing topic and invite a nonmember to a private message or topic can control markup in the recipient's email body.

CVSS severity7.1
High
EPSS probability0.26%
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

HTML injection in Discourse before 3.4.4, 3.5.0.beta5, or 3.5.0.beta6-dev allows remote authenticated users to alter invitation emails. The invite mailer inserts a topic title containing HTML into the invite_mailer template's {topic_title} field without neutralizing markup. An account able to create an HTML-bearing topic and invite a nonmember to a private message or topic can control markup in the recipient's email body.

The record

CVE
CVE-2025-48062
Published
Jun 9, 2025
Updated
Jun 9, 2025
Vendor
Discourse
Product
Discourse
Classifications
CWE-79, CWE-116
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 9, 2025CVE publishedPublication date reported by the CVE source.
  2. Jun 9, 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=< 3.4.4
  2. Affected versionversion=< 3.5.0.beta5
  3. Affected versionversion=< 3.5.0.beta6-dev

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Discourse · Discourseversion=< 3.4.4; version=< 3.5.0.beta5; version=< 3.5.0.beta6-dev

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
7.1GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-116Improper Encoding or Escaping of Output

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