Vulnerability in Knadh Listmonk
CVE-2025-49136
listmonk is a standalone, self-hosted, newsletter and mailing list manager. Starting in version 4.0.0 and prior to version 5.0.2, the `env` and `expandenv` template functions which is enabled by default in Sprig enables capturing of env variables on host. While this may not be a problem on single-user (super admin) installations, on multi-user installations, this allows non-super-admin users with campaign or template permissions to use the `{{ env }}` template expression to capture sensitive environment variables. Users should upgrade to v5.0.2 to mitigate the issue.
EPSS: 0.009 (56.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H.
Affected products
- Knadh Listmonk — versions >= 4.0.0, < 5.0.2
- Nadh Listmonk
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2025-49136?
- CVE-2025-49136 is a critical-severity vulnerability in Knadh Listmonk, classified under Improper Neutralization of Special Elements Used in a Template Engine. CVSS score: 9.0/10. Published 2025-06-09.
- How severe is CVE-2025-49136?
- Critical severity. CVSS v3 base score is 9.0 out of 10.
- Is CVE-2025-49136 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.