How severe is CVE-2025-49136?

CVE-2025-49136 has a CVSS score of 9/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2025-49136?

CVE-2025-49136 affects the following packages: github.com/knadh/listmonk (Go). Ecosystems affected: Go.

How do I fix CVE-2025-49136?

Update github.com/knadh/listmonk to 5.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-49136 is resolved across your whole dependency graph.

How do I detect CVE-2025-49136 in my Go dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/knadh/listmonk. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2025-49136 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2025-49136?

O3 pinpoints whether CVE-2025-49136 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2025-49136 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-49136 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-49136?

CVE-2025-49136 has an EPSS (Exploit Prediction Scoring System) score of 0.9%, placing it in the 55th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2025-49136 published, and has it been updated?

CVE-2025-49136 was published on June 9, 2025 and was last updated on April 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐹 Go

CVE-2025-49136

CRITICAL

listmonk's Sprig template Injection vulnerability leads to reading of Environment Variable for low privilege user

Also known asGHSA-jc7g-x28f-3v3hGO-2025-3745

Published

Jun 9, 2025

Updated

Apr 2, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.9%probability of exploitation in next 30 days

Lower Risk55th percentile-60.88%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Blast Radius

1 pkg affected

🐹github.com/knadh/listmonk

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.

Description

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.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐹Go	`github.com/knadh/listmonk`	≥ 4.0.0&&< 5.0.2	5.0.2

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/knadh/listmonk. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update github.com/knadh/listmonk to 5.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-49136 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-49136 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2025-49136. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

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.

O3 Security · Impact-Aware SCA

Is CVE-2025-49136 in your dependencies?

O3 detects CVE-2025-49136 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works