How severe is CVE-2026-46391?

No CVSS score has been assigned to CVE-2026-46391 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-46391?

CVE-2026-46391 affects the following packages: @haxtheweb/open-apis (npm). Ecosystems affected: npm.

How do I fix CVE-2026-46391?

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.

How do I detect CVE-2026-46391 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @haxtheweb/open-apis, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-46391 if there is no patch (or I can't update yet)?

Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Is CVE-2026-46391 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-46391 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-2026-46391?

CVE-2026-46391 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 40th 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.

What type of vulnerability is CVE-2026-46391?

CVE-2026-46391 is classified as CWE-183 (CWE-183), Server-Side Request Forgery (SSRF) (CWE-918). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-46391 published, and has it been updated?

CVE-2026-46391 was published on May 19, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

CVE-2026-46391 — @haxtheweb/open-apis

CVE-2026-46391 is a CWE-183 vulnerability in @haxtheweb/open-apis. A fix is available for @haxtheweb/open-apis — see the affected versions and patch details below.

HAX open-apis: Credential Theft via Server-Side Request Forgery (SSRF) in open-apis

Published

May 19, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

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

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs40th percentile — riskier than 40% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

@haxtheweb/open-apisnpm

158downloads / week

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

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@haxtheweb/open-apis`	all versions	26.0.0`npm install @haxtheweb/open-apis@26.0.0`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @haxtheweb/open-apis, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
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
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Frequently Asked Questions

### 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](https://github.com/haxtheweb/open-apis/blob/ff694ce91442c39ae1a78dc21e9ce50546aa207a/api/services/website/cacheAddress.js#L21), [api/apps/haxcms/lib/JOSHelpers.js](https://github.com/haxtheweb/open-apis/blob/ff694ce91442c39ae1a78dc21e9ce50546aa207a/api/apps/haxcms/lib/JOSHelpers.js#L26), and [api/apps/haxcms

O3 Security · Impact-Aware SCA

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