CVE-2026-56835: CWE-862: Missing Authorization in MervinPraison PraisonAI

CVE-2026-56835 describes a missing authorization vulnerability (CWE-862) in MervinPraison's PraisonAI Slack bot. Between versions 3.11.0 and before 4.6.59, the bot applies configured allowed_users, allowed_channels, and unknown_user_policy restrictions only in the normal Slack message event handler. However, the adjacent Slack app_mention event handler does not enforce these restrictions, allowing any Slack workspace user who can mention the bot in a channel where the app is present to trigger the PraisonAI agent regardless of configured access controls. This discrepancy leads to unauthorized triggering of agents even when policies deny such actions. The vulnerability was patched in version 4.6.59.

An attacker with the ability to mention the PraisonAI Slack bot in a channel where the app is installed can bypass configured user and channel restrictions, potentially triggering agent actions without authorization. This could lead to unauthorized information disclosure or manipulation within the Slack workspace. The CVSS 3.1 score of 8.3 (high severity) reflects the network attack vector, low attack complexity, required privileges, no user interaction, and high confidentiality and integrity impacts with low availability impact.

Upgrade PraisonAI to version 4.6.59 or later, where this missing authorization issue in the Slack app_mention event handler has been fixed. No other mitigation is required as the patch fully addresses the vulnerability.