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TI-2025-35897 Aliases CVE-2025-58054

Discourse is vulnerable to XSS when quoting chat messages

Priority LOW 24CWE-80Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-80.

Summary

Discourse is an open-source community discussion platform. Versions 3.5.0 and below are vulnerable to XSS attacks through parsing and rendering of chat channel titles and chat thread titles via the quote message functionality when using the rich text editor. This issue is fixed in version 3.5.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00208 10th percentileScored 2026-11-07
Fix Fixed discourse (discourse): 3.5.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
discoursediscoursebefore 3.5.13.5.1Patch availableCNA
  • discourse Vendordiscourse Affected before 3.5.1 Fixed in 3.5.1 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*before 3.5.0Vulnerablediscourse
cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:*before 3.6.0Vulnerablediscourse
cpe:2.3:a:discourse:discourse:3.6.0:beta1:*:*:beta:*:*:*3.6.0 beta1Vulnerablediscourse
  • cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:* Versions before 3.5.0 Vulnerable ·discourse
  • cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:* Versions before 3.6.0 Vulnerable ·discourse
  • cpe:2.3:a:discourse:discourse:3.6.0:beta1:*:*:beta:*:*:* Versions 3.6.0 beta1 Vulnerable ·discourse

Remediation

  • Fix · CNA discourse (discourse) Fixed in 3.5.1

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-58054

References

Patch 1

Advisory 1

  • TI-2021-19656 Denial of Service in discourse CVSS 3.1MEDIUM 6.8
  • TI-2024-36150 Potential Backup file leaked via Nginx in Discourse CVSS 3.1HIGH 7.5
  • TI-2021-18002 RCE via malicious SNS subscription payload CVSS 3.1CRITICAL 10.0
  • TI-2026-24651 Discourse: Open redirect via `sso_destination_url` cookie in `enter` CVSS 4.0MEDIUM 5.1
  • TI-2026-22278 Discourse leaks private topic title and post excerpt via user action API endpoint CVSS 4.0HIGH 8.7
  • TI-2023-24152 Unauthenticated access to new private chat messages in Discourse CVSS 3.1HIGH 7.5
See all 262 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences