SB2026012948 - Multiple vulnerabilities in Discourse



SB2026012948 - Multiple vulnerabilities in Discourse

Published: January 29, 2026

Security Bulletin ID SB2026012948
Severity
Medium
Patch available
YES
Number of vulnerabilities 13
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Medium 62% Low 38%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 13 secuirty vulnerabilities.


1) Stored cross-site scripting (CVE-ID: CVE-2025-66488)

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data within S3 for uploads. A remote user can inject and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.


2) Incorrect authorization (CVE-ID: CVE-2025-68660)

The vulnerability allows a remote attacker to bypass authorization process.

The vulnerability exists due to incorrect authorization. A remote user can bypass the ai_discover_persona access controls to impersonate user.


3) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2025-68659)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to allocation of resources without limits or throttling in username change endpoint. A remote user can pass specially crafted input to the application and perform a denial of service (DoS) attack.


4) Incorrect authorization (CVE-ID: CVE-2025-68666)

The vulnerability allows a remote user to bypass authorization process.

The vulnerability exists due to incorrect authorization. A remote administrator can view users archives.


5) Incorrect authorization (CVE-ID: CVE-2025-69218)

The vulnerability allows a remote attacker to bypass authorization process.

The vulnerability exists due to incorrect authorization. A remote user can access the top_uploads admin report to gain access to sensitive information.


6) Incorrect authorization (CVE-ID: CVE-2025-69289)

The vulnerability allows a remote user to bypass authorization process.

The vulnerability exists due to insecure default configuration. A remote administrator can bypass email-change restrictions and takeover non-staff accounts.


7) Incorrect authorization (CVE-ID: CVE-2026-24742)

The vulnerability allows a remote attacker to bypass authorization process.

The vulnerability exists due to incorrect authorization. A remote user can view sensitive information in staff action logs.


8) Missing Authorization (CVE-ID: CVE-2025-68479)

The vulnerability allows a remote attacker to bypass authorization process.

The vulnerability exists due to subscription endpoints lack proper checking for ownership before making changes. A remote user can takeover subscriptions.


9) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2025-68662)

The disclosed vulnerability allows a remote attacker to perform SSRF attacks.

The vulnerability exists due to hostname validation issue in FinalDestination. A remote user can send a specially crafted HTTP request and trick the application to initiate requests to arbitrary systems.

Successful exploitation of this vulnerability may allow a remote attacker gain access to sensitive data, located in the local network or send malicious requests to other servers from the vulnerable system.


10) Information disclosure (CVE-ID: CVE-2026-23743)

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to permalinks to restricted resources leak resource slugs. A remote attacker can gain unauthorized access to sensitive information on the system.


11) Missing Authorization (CVE-ID: CVE-2026-21865)

The vulnerability allows a remote user to bypass authorization process.

The vulnerability exists due to missing authorization. A remote administrator can convert some personal messages to public topics.


12) Incorrect authorization (CVE-ID: CVE-2025-68933)

The vulnerability allows a remote user to bypass authorization process.

The vulnerability exists due to incorrect authorization. A remote administrator can change ownership of posts in private messages and restricted categories they cannot access to exfiltrate private content.


13) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2025-68934)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to allocation of resources without limits or throttling in Drafts Creation Endpoint. A remote user can pass specially crafted input to the application and perform a denial of service (DoS) attack.


Remediation

Install update from vendor's website.