CVE-2026-56837 Details
Description
PraisonAI is a multi-agent teams system. From version 4.6.56 to before version 4.6.59, PraisonAI's LinearBot starts a public webhook listener on 0.0.0.0 and treats LINEAR_WEBHOOK_SECRET as optional. When the secret is absent, startup only logs a warning and _handle_webhook() skips Linear-Signature verification entirely. An unauthenticated network caller who can reach the webhook endpoint can submit a forged Linear-Event: AgentSession request. The forged request is parsed, scheduled for background processing, dispatched to _handle_agent_session(), and passed into BotSessionManager.chat(). The bot then attempts to post the agent response back to Linear under the configured bot token. The PoV is offline and deterministic. It does not contact Linear. It calls the webhook handler directly, monkey-patches the outbound Linear comment path, and proves both sides of the boundary. This issue has been patched in version 4.6.59.
A vulnerability exists in PraisonAI's LinearBot, specifically in versions 4.6.56 prior to 4.6.59. The bot initiates a public webhook listener on all interfaces and considers the LINEAR_WEBHOOK_SECRET optional. When the secret is not provided, the bot logs a warning and bypasses the Linear-Signature verification. This allows an unauthenticated network caller to send a forged Linear-Event: AgentSession request to the webhook. The request is processed in the background, routed to the appropriate handler, and can manipulate the bot's interactions with Linear, including posting comments under the bot's identity. The issue has been resolved in version 4.6.59.
Users should ensure that the LINEAR_WEBHOOK_SECRET is configured correctly and that the bot is not exposed to the public without proper authentication. Update to PraisonAI version 4.6.59 or later, where this vulnerability has been patched.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Oct 23, 2026CISA-ADP
Assessed Oct 23, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-fc26-m9pf-v56q | [email protected] | AdvisoryExploitRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-287 | Improper Authentication | [email protected] |
| CWE-306 | Missing Authentication for Critical Function | [email protected] |
| CWE-347 | Improper Verification of Cryptographic Signature | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| MervinPraison PraisonAI | >= 4.6.56, <= 4.6.58 (semver) >= 4.5.50 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Oct 23, 2026 | CVE Modified | CISA-ADP |
| Oct 23, 2026 | New CVE Received | [email protected] |