What is CVE-2020-13121?

CVE-2020-13121 is a medium-severity vulnerability in Rcos Submitty, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2020-05-16.

How severe is CVE-2020-13121?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2020-13121 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Open Redirect in Rcos Submitty

CVE-2020-13121

Submitty through 20.04.01 has an open redirect via authentication/login?old= during an invalid login attempt.

Vulnerability class: Open Redirect

Published 2020-05-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.029 (86.6th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 87th percentile — 86.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.030 · newest: 0.029 · change: -0.000

Affected products

Rcos Submitty

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

Public proof-of-concept exploits

References

github.com/Submitty/Submitty/issues/5265 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2020-13121?: CVE-2020-13121 is a medium-severity vulnerability in Rcos Submitty, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2020-05-16.
How severe is CVE-2020-13121?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2020-13121 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.