GHSA-8v65-47jx-7mfr
MEDIUMMailpit Proxy Endpoint has Server-Side Request Forgery (SSRF) vulnerability
EPSS Exploitation Probability
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
github.com/axllent/mailpitReal-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
Summary
A Server-Side Request Forgery (SSRF) vulnerability exists in Mailpit's /proxy endpoint that allows attackers to make requests to internal network resources.
Description
The /proxy endpoint allows requests to internal network resources. While it validates http:// and https:// schemes, it does not block internal IP addresses, allowing attackers to access internal services and APIs.
Proof of Concept
Basic SSRF Request
GET /proxy?url=http://127.0.0.1:8025/api/v1/info
This returns internal API data including database path and runtime statistics.
Impact Assessment
1. Internal Network Scanning
Attacker can probe and discover internal services on the network.
2. Information Disclosure
Access to internal API data, database paths, and runtime statistics.
3. Email Content Access
Ability to read all captured emails via internal API endpoints.
4. Cloud Metadata Access
If deployed in cloud environments (AWS/GCP/Azure), potential access to instance metadata services (e.g., http://169.254.169.254/).
Attack Scenarios
Scenario 1: Development Environment Exposure
If Mailpit is accidentally exposed to the internet, attackers can leverage SSRF to access internal development resources and services.
Scenario 2: Container Escape Information
In containerized deployments, SSRF can reveal container metadata and internal service configurations.
Scenario 3: Lateral Movement
In corporate networks, SSRF can be used to discover and interact with internal services, facilitating lateral movement.
Mitigating Factors
This vulnerability is limited to HTTP GET requests with minimal headers. Additionally, Mailpit's web UI & API should be protected by basic authentication when exposed to the internet, which prevents access to the proxy endpoint.
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/axllent/mailpit | all versions | 1.28.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/axllent/mailpit. 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/axllent/mailpit to 1.28.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-8v65-47jx-7mfr 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 GHSA-8v65-47jx-7mfr 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 GHSA-8v65-47jx-7mfr. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-8v65-47jx-7mfr in your dependencies?
O3 detects GHSA-8v65-47jx-7mfr across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.