How severe is CVE-2026-33277?

High severity. CVSS v3 base score is 8.8 out of 10.

RCE in Japan Computer Emergency Response Team Coordination Center (Jpcert/cc) Logontracer

CVE-2026-33277

An OS command Injection issue exists in LogonTracer prior to v2.0.0. An arbitrary OS command may be executed by a logged-in user.

Vulnerability class: Command Injection (OS Command Injection)

Published 2026-04-27 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.023 (82.7th percentile), scored 2026-10-19.

Low probability of exploitation in the next 30 days, but still tracked. 83rd percentile — 82.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.023 · change: +0.009

Affected products

Japan Computer Emergency Response Team Coordination Center (Jpcert/cc) Logontracer — versions prior to v2.0.0
Jpcert Logontracer

Weakness classification (CWE)

CWE-78 — OS Command Injection

References

www.jpcert.or.jp/press/2026/PR20260423.html (Third Party Advisory)
jvn.jp/en/jp/JVN57877356/ (Third Party Advisory)

Frequently asked questions

What is CVE-2026-33277?: CVE-2026-33277 is a high-severity vulnerability in Japan Computer Emergency Response Team Coordination Center (Jpcert/cc) Logontracer, classified under OS Command Injection. CVSS score: 8.8/10. Published 2026-04-27.
How severe is CVE-2026-33277?: High severity. CVSS v3 base score is 8.8 out of 10.