CVE-2021-3116
CVSS v3
7.5
HIGH
EPSS Score
1.7 %
exploit probability, as of 2026-09-25
CISA KEV
No
known exploited
Exploitation
—
SSVC status
Description
before_upstream_connection in AuthPlugin in http/proxy/auth.py in proxy.py before 2.3.1 accepts incorrect Proxy-Authorization header data because of a boolean confusion (and versus or).
Technical details
- Published
- 2021-01-11
Frequently asked questions
What is CVE-2021-3116?
before_upstream_connection in AuthPlugin in http/proxy/auth.py in proxy.py before 2.3.1 accepts incorrect Proxy-Authorization header data because of a boolean confusion (and versus or).
Is CVE-2021-3116 actively exploited?
Active exploitation of CVE-2021-3116 has not been confirmed. Its EPSS score was 1.7% on 2026-09-25, the estimated probability of exploitation in the next 30 days.
What is the CVSS score for CVE-2021-3116?
CVE-2021-3116 has a CVSS v3 base score of 7.5 (HIGH severity).
Is CVE-2021-3116 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).