How severe is GHSA-4mxg-3p6v-xgq3?

GHSA-4mxg-3p6v-xgq3 has a CVSS score of 10/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by GHSA-4mxg-3p6v-xgq3?

GHSA-4mxg-3p6v-xgq3 affects the following packages: @node-saml/node-saml (npm), passport-saml (npm), @node-saml/passport-saml (npm). Ecosystems affected: npm.

How do I fix GHSA-4mxg-3p6v-xgq3?

Update @node-saml/node-saml to 5.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4mxg-3p6v-xgq3 is resolved across your whole dependency graph.

How do I detect GHSA-4mxg-3p6v-xgq3 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @node-saml/node-saml. 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 GHSA-4mxg-3p6v-xgq3 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 GHSA-4mxg-3p6v-xgq3?

O3 pinpoints whether GHSA-4mxg-3p6v-xgq3 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 GHSA-4mxg-3p6v-xgq3 actively exploited in the wild?

No public exploit code has been indexed for GHSA-4mxg-3p6v-xgq3 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 GHSA-4mxg-3p6v-xgq3?

GHSA-4mxg-3p6v-xgq3 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 26th 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 GHSA-4mxg-3p6v-xgq3?

GHSA-4mxg-3p6v-xgq3 is classified as Improper Authentication (CWE-287), CWE-347 (CWE-347). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-4mxg-3p6v-xgq3 published, and has it been updated?

GHSA-4mxg-3p6v-xgq3 was published on July 28, 2025 and was last updated on August 8, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

GHSA-4mxg-3p6v-xgq3

CRITICAL

Node-SAML SAML Signature Verification Vulnerability

Also known asCVE-2025-54419

Published

Jul 28, 2025

Updated

Aug 8, 2025

Affected

3 pkgs

Patched

2 / 3

Exploits

None indexed

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk26th percentile+0.21%

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

3 pkgs affected

Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.

@node-saml/node-samlnpm

702Kdownloads / week

passport-samlnpm

144Kdownloads / week

@node-saml/passport-samlnpm

438Kdownloads / week

Description

Node-SAML loads the assertion from the (unsigned) original response document. This is different than the parts that are verified when checking signature.

This allows an attacker to modify authentication details within a valid SAML assertion. For example, in one attack it is possible to remove any character from the SAML assertion username.

To conduct the attack an attacker would need a validly signed document from the identity provider (IdP).

In fixing this we made sure to process the SAML assertions from only verified/authenticated contents. This will prevent future variants from coming up.

Note: this is distinct from the previous xml-crypto CVEs.

Affected Packages

3 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`@node-saml/node-saml`	all versions	5.1.0
📦npm	`passport-saml`	all versions	No fix
📦npm	`@node-saml/passport-saml`	all versions	5.1.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @node-saml/node-saml. 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 @node-saml/node-saml to 5.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4mxg-3p6v-xgq3 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-4mxg-3p6v-xgq3 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-4mxg-3p6v-xgq3. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

Node-SAML loads the assertion from the (unsigned) original response document. This is different than the parts that are verified when checking signature. This allows an attacker to modify authentication details within a valid SAML assertion. For example, in one attack it is possible to remove any character from the SAML assertion username. To conduct the attack an attacker would need a validly signed document from the identity provider (IdP). In fixing this we made sure to process the SAML assertions from only verified/authenticated contents. This will prevent future variants from coming up

O3 Security · Impact-Aware SCA

Is GHSA-4mxg-3p6v-xgq3 in your dependencies?

O3 detects GHSA-4mxg-3p6v-xgq3 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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