What is CVE-2020-5561?

CVE-2020-5561 is a critical-severity vulnerability in Keijiban Tsumiki Project, classified under OS Command Injection. CVSS score: 9.8/10. Published 2020-03-25.

How severe is CVE-2020-5561?

Critical severity. CVSS v3 base score is 9.8 out of 10.

RCE in Keijiban Tsumiki Project

CVE-2020-5561

Keijiban Tsumiki v1.15 allows remote attackers to execute arbitrary OS commands via unspecified vectors.

Vulnerability class: Command Injection (OS Command Injection)

Published 2020-03-25 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.023 (82.5th percentile), scored 2026-10-02.

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 82.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.023 · newest: 0.023 · change: 0.000

Affected products

Keijiban Tsumiki Project — versions 1.15
Mash Room - Free Cgi Keijiban Tsumiki — versions v1.15

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

jvn.jp/en/jp/JVN88277644/index.html (Third Party Advisory)

Frequently asked questions

What is CVE-2020-5561?: CVE-2020-5561 is a critical-severity vulnerability in Keijiban Tsumiki Project, classified under OS Command Injection. CVSS score: 9.8/10. Published 2020-03-25.
How severe is CVE-2020-5561?: Critical severity. CVSS v3 base score is 9.8 out of 10.