CVE-2026-111367

MEDIUM 6.5

BillionMail through 4.9 Forgeable JWTs via Default Signing Key

CVSS Score

6.5

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-1394
Vendor	aapanel
Product	billionmail
Published	Oct 15, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

Low

Availability

Low

Affected Versions

aaPanel / BillionMail

0 ≤ 4.9

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

hieuPenguinnn