CVE-2020-26938
This allows a malicious client to pass an XSS payload through the redirect_uri parameter while making an authorization request.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.99%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.2 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- EPSS
- 0.99% probability · 62th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-601
- Affected
- oauth2-server project/oauth2-server
- Source
- cve@mitre.org
EPSS 1.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/oauthjs/node-oauth2-server/blob/91d2cbe70a0eddc53d72def96864e2de0fd41703/lib/grant-types/authorization-code-grant-type.js#L143Exploit, Third Party Advisory
- https://github.com/oauthjs/node-oauth2-server/blob/91d2cbe70a0eddc53d72def96864e2de0fd41703/lib/validator/is.js#L12Exploit, Third Party Advisory
- https://github.com/oauthjs/node-oauth2-server/issues/637Issue Tracking, Third Party Advisory
- https://tools.ietf.org/html/rfc3986#section-3Third Party Advisory
- https://tools.ietf.org/html/rfc6749#section-3.1.2Third Party Advisory
- https://github.com/oauthjs/node-oauth2-server/blob/91d2cbe70a0eddc53d72def96864e2de0fd41703/lib/grant-types/authorization-code-grant-type.js#L143Exploit, Third Party Advisory
- https://github.com/oauthjs/node-oauth2-server/blob/91d2cbe70a0eddc53d72def96864e2de0fd41703/lib/validator/is.js#L12Exploit, Third Party Advisory
- https://github.com/oauthjs/node-oauth2-server/issues/637Issue Tracking, Third Party Advisory
- https://tools.ietf.org/html/rfc3986#section-3Third Party Advisory
- https://tools.ietf.org/html/rfc6749#section-3.1.2Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.