CVE-2026-56837
PraisonAI LinearBot processes unsigned webhooks when LINEAR_WEBHOOK_SECRET is missing
At a glance
- Source
- NVD
- EPSS
- EPSS 0.19 % · percentile 8 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD 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.
Weaknesses (CWE)
- CWE-287 — Improper Authentication
- CWE-306 — Missing Authentication for Critical Functionality
- CWE-347 — Improper Verification of Cryptographic Signature
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L | GitHub_M |
| CVSS 3.1 | HIGH 8.6 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:L | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-fc26-m9pf-v56q — PraisonAI LinearBot processes unsigned webhooks when LINEAR_WEBHOOK_SECRET is missing
- PYSEC-2026-3510 — PraisonAI LinearBot processes unsigned webhooks when LINEAR_WEBHOOK_SECRET is missing
European references
- ENISA EUVD · EUVD-2026-108878
- GCVE · GCVE-0-2026-56837
Affected products
| Product | Versions |
|---|---|
| MervinPraison · PraisonAI | affected >= 4.6.56, < 4.6.59 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |