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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
aaPanel BillionMail unaffected
Version Status Constraints
0 affected ≤ 4.9

No data.

No data.

No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

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

Thu, 15 Oct 2026 22:00:00 +0000

Type Values Removed Values Added
Description 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.
Title BillionMail through 4.9 Forgeable JWTs via Default Signing Key
Weaknesses CWE-1394
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L'}

cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-15T21:43:50.886Z

Reserved: 2026-10-15T21:21:22.403Z

Link: CVE-2026-111367

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-15T22:19:34.703

Modified: 2026-10-15T22:19:34.703

Link: CVE-2026-111367

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses