CVE-2026-41213: @node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js

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MEDIUM 5.9REMOTEUPGRADE

CVE-2026-41213 is a medium-severity flaw (CVSS 5.9) affecting node-oauth\/oauth2-server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

@node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js. The token exchange path accepts RFC7636-invalid code_verifier values (including one-character strings) for S256 PKCE flows. Because short/weak verifiers are accepted and failed verifier attempts do not consume the authorization code, an attacker who intercepts an authorization code can brute-force code_verifier guesses online until token issuance succeeds.

Why this priority

Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	5.9 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.3% (top 83%)
CISA exploited list	No
Weakness	CWE-307, CWE-1289
Published	2026-04-23
Last modified	2026-10-26

Publisher (CNA): GitHub, Inc. · Vendor: node-oauth

Last updated 2026-10-26 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-04-23 19:17 UTCPublished CVE record published
2026-10-26 21:10 UTCUpdated Record last modified

node-oauth node-oauth\/oauth2-server UPGRADE

Affected: < 5.3.0

Fixed in: 5.3.0

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls node-oauthoauth2-server

2. UPGRADE to 5.3.0

npm install node-oauthoauth2-server@">=5.3.0"

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-41213?

node-oauth\/oauth2-server: upgrade to 5.3.0. Exact commands for each OS are on this page.

Is CVE-2026-41213 being exploited?

CVE-2026-41213 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-41213 affect?

CVE-2026-41213 affects node-oauth\/oauth2-server. Severity is medium (CVSS 5.9). @node-oauth/oauth2-server is a module for implementing an OAuth2 server in Node.js. The token exchange path accepts RFC7636-invalid code_verifier values (including one-character strings) for S256 PKCE flows. Because short/weak verifiers are

How urgent is CVE-2026-41213?

Priority 35/100. Public exploit reference; Remotely exploitable, no login, no user action

Software pages

Node.js vulnerabilities

References

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