CVE-2026-56837

Published: Ott 23, 2026 Last Modified: Ott 23, 2026
ExploitDB:
Other exploit source:
Google Dorks:
HIGH 8,6
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Scope: unchanged
Confidentiality: low
Integrity: high
Availability: low

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.

287

Improper Authentication

Draft
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Availability Access Control
Potential Impacts:
Read Application Data Gain Privileges Or Assume Identity Execute Unauthorized Code Or Commands
Applicable Platforms
Technologies: Not Technology-Specific, Web Based, ICS/OT
Likelihood of Exploit: High
View CWE Details
306

Missing Authentication for Critical Function

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control Other
Potential Impacts:
Gain Privileges Or Assume Identity Varies By Context
Applicable Platforms
Technologies: Cloud Computing, ICS/OT
Likelihood of Exploit: High
View CWE Details
347

Improper Verification of Cryptographic Signature

Draft
Abstraction: Base Structure: Simple
Common Consequences
Security Scopes Affected:
Access Control Integrity Confidentiality
Potential Impacts:
Gain Privileges Or Assume Identity Modify Application Data Execute Unauthorized Code Or Commands
Applicable Platforms
All platforms may be affected
View CWE Details
https://github.com/MervinPraison/PraisonAI/security/advisor…
https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-fc26-m9pf-v…