{"cve":"CVE-2026-56837","nvd":{"published":"2026-10-23T12:18:15.203","modified":"2026-10-23T21:17:24.307","status":"Deferred","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L","score":8.6},"cwes":["CWE-287","CWE-306","CWE-347"],"references":["https://github.com/MervinPraison/PraisonAI/security/advisories/GHSA-fc26-m9pf-v56q"],"products":[],"source":"nvd","synced_at":"2026-10-24T16:53:35.584907681+00:00"},"epss":{"cve":"CVE-2026-56837","score":0.00188,"percentile":0.083,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-fc26-m9pf-v56q","url":"https://osv.dev/vulnerability/GHSA-fc26-m9pf-v56q","summary":"PraisonAI LinearBot processes unsigned webhooks when LINEAR_WEBHOOK_SECRET is missing","modified":"2026-07-23T15:11:39.851493687Z","packages":[{"ecosystem":"PyPI","name":"praisonai","purl":"pkg:pypi/praisonai","ranges":[">=4.6.56 <4.6.59"],"fixed":["4.6.59"]}]},{"id":"PYSEC-2026-3510","url":"https://osv.dev/vulnerability/PYSEC-2026-3510","summary":"PraisonAI LinearBot processes unsigned webhooks when LINEAR_WEBHOOK_SECRET is missing","modified":"2026-07-23T15:00:20.789202469Z","packages":[{"ecosystem":"PyPI","name":"praisonai","purl":"pkg:pypi/praisonai","ranges":[">=4.6.56 <4.6.59"],"fixed":["4.6.59"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}