GHSA-77fw-rf4v-vfp9 is a high-severity (CVSS 8.1) CWE-290 vulnerability in passport-wsfed-saml2. A fix is available for passport-wsfed-saml2 — see the affected versions and patch details below.
passport-wsfed-saml2 vulnerable to Signature Bypass in SAML2 token
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.
How urgent is this, really
GHSA-77fw-rf4v-vfp9 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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.
passport-wsfed-saml2npmDescription
Information
Please note that this is not a new disclosure, and is previously reported in our SECURITY-NOTICE.md which we removed in favor of github advisory.
Overview
This vulnerability allows an attacker to impersonate another user and potentially elevate their privileges if the SAML identity provider:
-
signs SAML response and signs assertion
-
does not sign SAML response and signs assertion
Am I affected?
You may be affected if you use SAML2 protocol with passport-wsfed-saml2 versions below 3.0.5 and your SAML identity Provider:
- signs SAML response and signs assertion; or
- does not sign SAML response and signs assertion
How do I fix it?
You may fix this vulnerability by upgrading your library to version 3.0.5 or above.
Will the fix impact my users?
This fix patches the library that your application runs, but will not impact your users, their current state, or any existing sessions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | passport-wsfed-saml2 | all versions | 3.0.5npm install passport-wsfed-saml2@3.0.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for passport-wsfed-saml2, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update passport-wsfed-saml2 to 3.0.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-77fw-rf4v-vfp9 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-77fw-rf4v-vfp9 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-77fw-rf4v-vfp9. 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-77fw-rf4v-vfp9 in your dependencies?
O3 Security finds GHSA-77fw-rf4v-vfp9 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.