CVE-2026-46391
CVE-2026-46391 is a CWE-183 vulnerability in @haxtheweb/open-apis. O3 Security confirms whether CVE-2026-46391 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
HAX open-apis: Credential Theft via Server-Side Request Forgery (SSRF) in open-apis
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-46391.
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.
Real-World Exposure
@haxtheweb/open-apisReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Multiple functions conduct substring-only matching to validate hostnames to which basic authorization should be sent. An attacker can append the matched substrings to an attacker-controlled endpoint and capture authentication.
Details
api/services/website/cacheAddress.js, api/apps/haxcms/lib/JOSHelpers.js, and api/apps/haxcms/convert/elmslnToSite.js use similar logic to check for hard-coded site names. However, the logic only looks for the substring to be included in the user-controlled string, allowing an attacker to craft an API call and extract the credentials intended for the hard-coded domains.
PoC
Making API calls to an affected endpoint will result in credential theft. The attacker-controlled domains in these proofs of concept are cloudflared tunnels, protecting the production credentials from unencrypted exposure.
cacheAddress.js: <img width="3404" height="1656" alt="ssrf_cred_theft" src="https://github.com/user-attachments/assets/0a87cef5-3c4d-450a-8bb7-35123d5f621b" />
elmslnToSite.js: <img width="3409" height="1641" alt="theft2" src="https://github.com/user-attachments/assets/bede82cc-a613-4fc7-bbf6-76166af784f5" />
JOSHelpers.js: <img width="3407" height="1597" alt="theft3" src="https://github.com/user-attachments/assets/4f3f8bee-443e-4b22-9d41-eb9726619d36" />
Impact
This vulnerability allows internal data, including secrets, to be exfiltrated to an attacker-controlled domain. Credentials were confirmed with the maintainer to grant access to unreleased LMS content on subsequent systems; out of scope for PoC.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @haxtheweb/open-apis | all versions | 26.0.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @haxtheweb/open-apis. 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 @haxtheweb/open-apis to 26.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-46391 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-2026-46391 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-2026-46391. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-46391 in your dependencies?
O3 detects CVE-2026-46391 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.