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CVE-2026-56837EUVD-2026-108878GHSA-FC26-M9PF-V56QPYSEC-2026-3510

PraisonAI LinearBot processes unsigned webhooks when LINEAR_WEBHOOK_SECRET is missing

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 4.6.59
None on Exploit-DB, Metasploit or GitHub
  • Exploitation: none
  • Automatable: yes
  • Technical impact: partial

Summary

PraisonAI's LinearBot webhook listener accepts unsigned requests when the LINEAR_WEBHOOK_SECRET environment variable is not set, so anyone who can reach the endpoint can inject forged agent session events that the bot will process and reply to in Linear using its configured bot token.

Summarized by anthropic/claude-haiku-5.5. Verify details against the original sources.

Read the original 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.

Timeline

  1. CVE published
  2. First seen by cve.now
  3. CISA SSVC assessment

    Exploitation: none · Automatable: yes · Technical impact: partial

  4. Record last updated

Affected versions

  • MervinPraison PraisonAI

    From 4.6.56 · fixed in 4.6.59

  • praisonaiPyPI

    From 4.6.56 · fixed in 4.6.59

References 1

GitHub · MervinPraison/PraisonAI