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.
Fix
Nothing published yet: no patch, vendor advisory or mitigation reference on NVD, no vendor advisory in the News for this CVE, not in CISA's KEV, no fixed package version. BaselineWatch does not guess at one.
Change history 2
- StatusReceived → DeferredNVD modified 2026-10-16 18:25
- First seenCVSS 6.9NVD modified 2026-10-15 22:19
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 6
- 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