What is CVE-2026-27787?

CVE-2026-27787 is a medium-severity vulnerability in Icz Matcha Sns, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-04-08.

How severe is CVE-2026-27787?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Icz Matcha Sns

CVE-2026-27787

Cross-site scripting vulnerability exists in MATCHA SNS 1.3.9 and earlier. If this vulnerability is exploited, an arbitrary script may be executed on the web browser of the user who accessed the website using the product.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2026-04-08 · last modified 2026-07-25.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (14.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Affected products

Icz Matcha Sns
Icz Corporation Matcha Sns — versions 1.3.9 and earlier

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

oss.icz.co.jp/news/ (Vendor Advisory)
jvn.jp/en/jp/JVN33581068/ (Third Party Advisory)

Frequently asked questions

What is CVE-2026-27787?: CVE-2026-27787 is a medium-severity vulnerability in Icz Matcha Sns, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2026-04-08.
How severe is CVE-2026-27787?: Medium severity. CVSS v3 base score is 5.4 out of 10.