listmonk 6.2.0 before 7.0.0-beta.2 contains a missing authentication vulnerability that allows unauthenticated
Source GCVE Database
Not known to be exploited · CVSS 6.3 Medium : upgrade to 7.0.0-beta.2 when convenient.
Data as of 13 Nov 2026, 13:32 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 6.3 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 4.8 |
- Patch
- Available – fixed in 7.0.0-beta.2
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 13 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Upgrade listmonk to 7.0.0-beta.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| knadhlistmonk | Affected
| Fixed in
|
Golistmonkpkg:golang/listmonkOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Users should configure a shared secret for Azure Event Grid bounce webhooks to enforce authentication and prevent unauthenticated POST requests. If you cannot patch yet, ensuring that webhook endpoints require authentication is the primary mitigation.
Description
listmonk versions 6.2.0 up to but not including 7.0.0-beta.2 have a missing authentication vulnerability. This flaw allows unauthenticated attackers to submit forged Azure Event Grid bounce webhook events when no shared secret is configured. Attackers can send POST requests with EmailDeliveryReportReceived events marked as Bounced to the /webhooks/service/azure endpoint, enabling them to blocklist, unsubscribe, or delete arbitrary subscribers without authorization.
References
- nvd.nist.gov/vuln/detail/CVE-2026-128334 (opens in a new tab)
- github.com/biofool/listmonk/issues/5 (opens in a new tab)
- github.com/knadh/listmonk/commit/0c155bd2663d9ec8053ac0d1ab63f021fbb5a0dc (opens in a new tab)
- github.com/knadh/listmonk/blob/v7.0.0-beta.1/internal/bounce/webhooks/azure.go (opens in a new tab)
- github.com/knadh/listmonk/releases/tag/v7.0.0-beta.2 (opens in a new tab)
- vulncheck.com/advisories/listmonk-6.2.0-before-7.0.0-beta.2-missing-authentication-via-azure-bounce-webhook (opens in a new tab)