# CVE-2026-111367: BillionMail JWT token forgery via hardcoded cryptographic key

Source: https://junglewise.ai/threats/cve-2026-111367-billionmail-through-4-9-contains-a-hard-coded-cryptographic-key  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-15. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-111367 · Severity: medium · CVSS 6.5 · Published 2026-10-15

BillionMail is an open-source email marketing and newsletter platform. The application uses a hardcoded cryptographic key to sign JWT tokens for unsubscribe and subscription confirmation requests, allowing unauthenticated attackers to forge valid tokens and deactivate email subscriptions or force confirmations on any contact without authorization.

Vendors: [aaPanel](https://junglewise.ai/threats/vendors/aapanel).

## Quick answers

**Is CVE-2026-111367 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-111367 being exploited in the wild.

**How severe is CVE-2026-111367?** Medium severity, with a CVSS score of 6.5, published 15 October 2026.

**Which products and versions are affected?** aaPanel BillionMail through 4.9.

**Is there a fix for CVE-2026-111367?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-111367 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-111367?** Check whether you run aaPanel BillionMail at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

BillionMail versions through 4.9 embed JWT secrets as hardcoded configuration constants (JWT_SECRET_KEY and SUBSCRIBE_CONFIRM_JWT_SECRET) in the batch_mail service. An unauthenticated network attacker can derive these keys from the shipped code and forge valid JWT tokens to submit to the /api/unsubscribe, /api/unsubscribe_new, and /api/subscribe/confirm endpoints, resulting in unauthorized manipulation of subscription states without authentication or user interaction.

## Affected products

- aaPanel BillionMail through 4.9

## Timeline

- 2026-10-15: disclosed

## References

- [https://github.com/aaPanel/BillionMail](https://github.com/aaPanel/BillionMail)
- [https://github.com/aaPanel/BillionMail/blob/v4.9/core/internal/service/batch_mail/jwt.go](https://github.com/aaPanel/BillionMail/blob/v4.9/core/internal/service/batch_mail/jwt.go)

## Related threats

- [aaPanel BillionMail injection in Relay Configuration API](https://junglewise.ai/threats/cve-2026-124579-a-vulnerability-was-determined-in-aapanel-billionmail-up-to-4-9)