CVE-2026-111367

BillionMail through 4.9 contains a hard-coded cryptographic key vulnerability that allows unauthenticated attackers to forge unsubscribe and subscribe-confirm JWTs by computing the key from shipped configuration constants. Attackers can submit forged tokens to /api/unsubscribe, /api/unsubscribe_new, or /api/subscribe/confirm to deactivate any contact or force confirmed subscriptions.

CVSS v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact LOW

Scope UNCHANGED

References

Link	Resource
https://github.com/aaPanel/BillionMail
https://github.com/aaPanel/BillionMail/blob/v4.9/core/internal/service/batch_mail/jwt.go#L98-L123
https://github.com/aaPanel/BillionMail/blob/v4.9/core/manifest/config/config.yaml
https://hackmd.io/@hieuPenguinnn/billionmail-unsubscribe-subscribe-jwt-deterministic-secret-forgery
https://www.vulncheck.com/advisories/billionmail-through-4.9-forgeable-jwts-via-default-signing-key
https://hackmd.io/@hieuPenguinnn/billionmail-unsubscribe-subscribe-jwt-deterministic-secret-forgery

Configurations

No configuration.

History

21 Oct 2026, 02:17

Type	Values Removed	Values Added
References	~~() https://hackmd.io/@hieuPenguinnn/billionmail-unsubscribe-subscribe-jwt-deterministic-secret-forgery -~~	() https://hackmd.io/@hieuPenguinnn/billionmail-unsubscribe-subscribe-jwt-deterministic-secret-forgery -

15 Oct 2026, 22:19

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-15 22:19

Updated : 2026-10-21 02:17

NVD link : CVE-2026-111367

Mitre link : CVE-2026-111367

CVE.ORG link : CVE-2026-111367

JSON object : View

Products Affected

No product.

CWE

CWE-1394

Use of Default Cryptographic Key

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