How severe is CVE-2021-41580?

CVE-2021-41580 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-41580?

CVE-2021-41580 affects the following packages: passport-oauth2 (npm). Ecosystems affected: npm.

How do I fix CVE-2021-41580?

Update passport-oauth2 to 1.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41580 is resolved across your whole dependency graph.

How do I detect CVE-2021-41580 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for passport-oauth2. 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 CVE-2021-41580 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 CVE-2021-41580?

O3 pinpoints whether CVE-2021-41580 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 CVE-2021-41580 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-41580 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-2021-41580?

CVE-2021-41580 has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 66th 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.

When was CVE-2021-41580 published, and has it been updated?

CVE-2021-41580 was published on September 27, 2021 and was last updated on April 2, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2021-41580: Improper Access Control in passport-oauth2 (Med…

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk66th percentile+0.79%

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

1 pkg affected

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

passport-oauth2npm

2.1Mdownloads / week

Description

The passport-oauth2 package before 1.6.1 for Node.js mishandles the error condition of failure to obtain an access token. This is exploitable in certain use cases where an OAuth identity provider uses an HTTP 200 status code for authentication-failure error reports, and an application grants authorization upon simply receiving the access token (i.e., does not try to use the token). NOTE: the passport-oauth2 vendor does not consider this a passport-oauth2 vulnerability

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`passport-oauth2`	all versions	1.6.1

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for passport-oauth2. 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 passport-oauth2 to 1.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-41580 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-2021-41580 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-2021-41580. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

The passport-oauth2 package before 1.6.1 for Node.js mishandles the error condition of failure to obtain an access token. This is exploitable in certain use cases where an OAuth identity provider uses an HTTP 200 status code for authentication-failure error reports, and an application grants authorization upon simply receiving the access token (i.e., does not try to use the token). NOTE: the passport-oauth2 vendor does not consider this a passport-oauth2 vulnerability

O3 Security · Impact-Aware SCA

Is CVE-2021-41580 in your dependencies?

O3 detects CVE-2021-41580 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works

CVE-2021-41580