CVE-2026-24742 in Discourse
Summary
by MITRE • 01/28/2026
Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, non-admin moderators can view sensitive information in staff action logs that should be restricted to administrators only. The exposed information includes webhook payload URLs and secrets, API key details, site setting changes, private message content, restricted category names and structures, and private chat channel titles. This allows moderators to bypass intended access controls and extract confidential data by monitoring the staff action logs. With leaked webhook secrets, an attacker could potentially spoof webhook events to integrated services. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. As a workaround, site administrators should review and limit moderator appointments to fully trusted users. There is no configuration-based workaround to prevent this access.
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Analysis
by VulDB Data Team • 01/29/2026
The vulnerability described in CVE-2026-24742 represents a critical access control flaw within the Discourse open source discussion platform that undermines the security model designed to protect sensitive administrative information. This issue affects multiple version branches including 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, indicating a widespread problem that has persisted across different release cycles. The flaw specifically targets the privilege separation mechanisms that should prevent non-administrative users from accessing staff action logs, creating a significant security gap in the platform's authorization framework.
The technical implementation of this vulnerability stems from inadequate access control validation within the staff action log viewing functionality. When non-admin moderators attempt to access these logs, the system fails to properly enforce role-based access controls that should restrict viewing permissions to administrators only. This allows unauthorized users to traverse the administrative interface and extract information that should remain confidential. The exposed data encompasses multiple categories of sensitive information including webhook payload URLs and secrets, which are particularly dangerous as they provide direct access to integrated third-party services. Additionally, API key details, site setting modifications, private message content, and restricted category structures are all accessible to unauthorized personnel.
The operational impact of this vulnerability extends beyond simple information disclosure to create potential attack vectors for more sophisticated compromises. The exposure of webhook secrets represents a severe risk as these credentials could enable attackers to forge webhook events and manipulate integrated services such as CI/CD pipelines, notification systems, or external automation tools. Private message content and restricted category structures provide attackers with insights into internal communications and organizational structure that could be leveraged for social engineering or targeted attacks. The ability to view site setting changes allows threat actors to identify recent configuration modifications that might reveal security weaknesses or indicate recent compromise attempts.
This vulnerability maps directly to CWE-285 (Improper Authorization) and aligns with several ATT&CK techniques including T1566 (Phishing) through the potential for using exposed credentials in social engineering attacks, T1071.004 (Application Layer Protocol: DNS) if webhook payloads are used to exfiltrate data, and T1531 (Account Access Removal) through potential abuse of elevated permissions. The lack of configuration-based workarounds means that administrators must rely entirely on user management practices, which creates operational challenges since the issue cannot be mitigated through simple setting changes. The patching requirements across multiple version branches indicate that this was a fundamental flaw in the authorization system rather than a localized issue.
Security practitioners should prioritize immediate remediation of this vulnerability by upgrading to the patched versions mentioned in the advisory. The recommended workaround of limiting moderator appointments to fully trusted users represents a temporary mitigation strategy that addresses the immediate risk while the platform is updated. However, this approach requires careful user vetting and ongoing monitoring to ensure that only legitimate administrators maintain access. Organizations should also implement additional monitoring of staff action logs to detect unauthorized access attempts and establish more robust access control policies that prevent similar issues from occurring in the future. The vulnerability highlights the critical importance of maintaining proper role separation in collaborative platforms and demonstrates how seemingly minor access control flaws can create significant security risks.