CVE-2020-26938 — oauth2-server
HIGHCVE-2020-26938 is a high-severity (CVSS 7.2) Open Redirect vulnerability in oauth2-server. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.
oauth2-server through 3.1.1 vulnerable to Open Redirect
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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.
oauth2-servernpmDescription
In oauth2-server (aka node-oauth2-server) through 3.1.1, the value of the redirect_uri parameter received during the authorization and token request is checked against an incorrect URI pattern ("[a-zA-Z][a-zA-Z0-9+.-]+:") before making a redirection. This allows a malicious client to pass an XSS payload through the redirect_uri parameter while making an authorization request. NOTE: this vulnerability is similar to CVE-2020-7741.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | oauth2-server | all versions | No fix |
Affected Products
oauth2-serveroauth2-server_projectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for oauth2-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
The records we use list no patched version of oauth2-server for CVE-2020-26938. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.
Mitigate without a patch
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
Frequently Asked Questions
Is CVE-2020-26938 in your dependencies?
Find it across npm, including transitive dependencies.