CVE-2021-26715
CVSS v3
9.1
CRITICAL
EPSS Score
1.5 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
The OpenID Connect server implementation for MITREid Connect through 1.3.3 contains a Server Side Request Forgery (SSRF) vulnerability. The vulnerability arises due to unsafe usage of the logo_uri parameter in the Dynamic Client Registration request. An unauthenticated attacker can make a HTTP request from the vulnerable server to any address in the internal network and obtain its response (which might, for example, have a JavaScript payload for resultant XSS). The issue can be exploited to bypass network boundaries, obtain sensitive data, or attack other hosts in the internal network.
Technical details
- Published
- 2021-03-25
Frequently asked questions
What is CVE-2021-26715?
The OpenID Connect server implementation for MITREid Connect through 1.3.3 contains a Server Side Request Forgery (SSRF) vulnerability. The vulnerability arises due to unsafe usage of the logo_uri parameter in the Dynamic Client Registration request. An unauthenticated attacker can make a HTTP request from the vulnerable server to any address in the internal network and obtain its response (which might, for example, have a JavaScript payload for resultant XSS). The issue can be exploited to bypass network boundaries, obtain sensitive data, or attack other hosts in the internal network.
Is CVE-2021-26715 actively exploited?
Active exploitation of CVE-2021-26715 has not been confirmed. Its EPSS score was 1.5% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-26715?
CVE-2021-26715 has a CVSS v3 base score of 9.1 (CRITICAL severity).
Is CVE-2021-26715 affecting your environment?
Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.
No credit card required · 500 free checks/month · Free API key
Other 2021 vulnerabilities worth triaging
Ranked by exploit probability (EPSS).