{"id":"CVE-2026-56837","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-56837","generatedAt":"2026-10-28T10:36:30.291Z","title":"PraisonAI is a multi-agent teams system.","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.","published":"2026-10-23T12:18:15.000Z","lastModified":"2026-10-23T21:17:24.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":8.6,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L"},"cwe":["CWE-287","CWE-306","CWE-347"],"affected":[],"epss":{"score":0.00188,"percentile":0.08302,"date":"2026-10-27","history":[{"date":"2026-10-24","score":0.00248,"percentile":0.15285}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.19%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-23T12:18:15.000Z","detail":{"score":"8.6","severity":"HIGH","publishedAt":"2026-10-23T12:18:15.203Z"},"summary":"New CVE, high severity (CVSS 8.6)."}],"references":[{"url":"https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-fc26-m9pf-v56q","source":"security-advisories@github.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-56837","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}