CVE-2026-15499: AstrBot Auth Bypass Vulnerability

CVE-2026-15499 Overview

CVE-2026-15499 is an improper authorization vulnerability [CWE-266] in AstrBotDevs AstrBot versions up to 4.25.2. The flaw resides in the FutureTaskTool.call function within astrbot/core/tools/cron_tools.py, part of the Scheduled Task Handler component. An authenticated remote attacker can manipulate the payload["note"] argument to bypass authorization controls. A public exploit has been released, increasing the likelihood of opportunistic abuse. The vendor was contacted before disclosure but did not respond.

Critical Impact
Remote attackers with low privileges can abuse the scheduled task handler to perform actions outside their authorization boundary, affecting confidentiality, integrity, and availability of the AstrBot instance.

Affected Products

AstrBotDevs AstrBot versions up to and including 4.25.2
Component: Scheduled Task Handler (astrbot/core/tools/cron_tools.py)
Affected function: FutureTaskTool.call

Discovery Timeline

2026-07-12 - CVE-2026-15499 published to NVD
2026-07-13 - Last updated in NVD database

Technical Details for CVE-2026-15499

Vulnerability Analysis

The vulnerability exists in AstrBot's scheduled task subsystem. The FutureTaskTool.call method accepts a payload dictionary containing a note field that is processed without adequate authorization checks. By manipulating this field, an authenticated attacker can trigger operations that should be restricted to higher-privileged users. The weakness is categorized as [CWE-266] Incorrect Privilege Assignment, meaning the code grants effective privileges beyond what the caller should possess.

Because AstrBot is typically deployed as a networked bot service, exploitation is possible over the network. The attack requires low privileges and no user interaction, and a proof-of-concept is publicly available on GitHub.

Root Cause

The root cause is missing or incorrect authorization enforcement inside FutureTaskTool.call. The function trusts caller-supplied fields in the payload dictionary to determine task behavior without validating whether the requesting principal is entitled to schedule or modify tasks with those attributes. This design allows a low-privilege user to influence execution paths intended for administrators.

Attack Vector

An attacker with valid low-privilege access to the AstrBot API submits a crafted scheduled task request containing a manipulated payload["note"] value. The Scheduled Task Handler processes the payload and dispatches the task without validating authorization against the caller's role. See the GitHub PoC Repository and VulDB CVE-2026-15499 for technical details of the exploitation flow.

Detection Methods for CVE-2026-15499

Indicators of Compromise

Unexpected scheduled task entries created by non-administrative user accounts within AstrBot.
API requests to the scheduled task endpoints containing unusual or crafted payload.note values.
Execution of scheduled tasks whose effects fall outside the initiating user's normal permission scope.

Detection Strategies

Audit AstrBot application logs for calls to FutureTaskTool.call correlated with low-privileged session identifiers.
Compare the requesting user's role against the privileges required by the resulting scheduled task action.
Alert on any modification of the cron or scheduled task store outside expected administrative maintenance windows.

Monitoring Recommendations

Enable verbose logging of authorization decisions within AstrBot and forward logs to a centralized SIEM for correlation.
Track a baseline of legitimate scheduled task creation patterns and alert on statistical deviations.
Monitor outbound network activity initiated by scheduled tasks for unexpected destinations that may indicate abuse.

How to Mitigate CVE-2026-15499

Immediate Actions Required

Restrict network exposure of the AstrBot management and API interfaces to trusted networks only.
Review and revoke unnecessary low-privilege accounts that can reach the scheduled task functionality.
Inspect existing scheduled tasks and remove any entries that cannot be attributed to a legitimate administrator.

Patch Information

At the time of publication, the vendor had not responded to the disclosure and no official fix is referenced in the advisory. Track the VulDB Vulnerability #377806 entry and the AstrBot project repository for a security release addressing versions after 4.25.2. Apply any subsequent patched release as soon as it is published.

Workarounds

Place AstrBot behind an authenticating reverse proxy that enforces stricter role-based access on scheduled task endpoints.
Disable or hot-patch the FutureTaskTool.call code path if scheduled tasks are not required for operational use.
Enforce network segmentation so that only administrative hosts can reach the AstrBot API surface.

bash

# Example: restrict access to AstrBot API using iptables
iptables -A INPUT -p tcp --dport 6185 -s 10.0.0.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 6185 -j DROP