What is CVE-2023-38998?

CVE-2023-38998 is a medium-severity vulnerability in Opnsense, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2023-08-09.

How severe is CVE-2023-38998?

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

Is CVE-2023-38998 known to be exploited?

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

Open Redirect in Opnsense

CVE-2023-38998

An open redirect in the Login page of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to redirect a victim user to an arbitrary web site via a crafted URL.

Vulnerability class: Open Redirect

Published 2023-08-09 · 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: 0.006 (46.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 46th percentile — 46.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Opnsense

Weakness classification (CWE)

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

Public proof-of-concept exploits

References

github.com/opnsense/core/commit/6bc025af1705dcdd8ef22ff5d4fcb986fa4e45f8 (Patch)
logicaltrust.net/blog/2023/08/opnsense.html (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2023-38998?: CVE-2023-38998 is a medium-severity vulnerability in Opnsense, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2023-08-09.
How severe is CVE-2023-38998?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2023-38998 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.