What is CVE-2023-5556?

CVE-2023-5556 is a medium-severity vulnerability in Structurizr On-Premises Installation, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-10-12.

How severe is CVE-2023-5556?

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

Is CVE-2023-5556 known to be exploited?

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

XSS in Structurizr On-Premises Installation

CVE-2023-5556

Cross-site Scripting (XSS) - Reflected in GitHub repository structurizr/onpremises prior to 3194.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2023-10-12 · 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: 0.012 (67.7th percentile), scored 2026-10-05.

Low probability of exploitation in the next 30 days, but still tracked. 68th percentile — 67.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Structurizr On-Premises Installation
Structurizr Structurizr/onpremises — versions unspecified

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

huntr.dev/bounties/a3ee0f98-6898-41ae-b1bd-242a03a73d1b (Exploit, Patch, Third Party Advisory)
github.com/structurizr/onpremises/commit/6cff4f792b010dfb1ff6a0b4ae1c6e398f8f8a… (Patch)

Frequently asked questions

What is CVE-2023-5556?: CVE-2023-5556 is a medium-severity vulnerability in Structurizr On-Premises Installation, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-10-12.
How severe is CVE-2023-5556?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2023-5556 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.