What is CVE-2026-42556?

CVE-2026-42556 is a high-severity vulnerability in Gitroom Postiz, classified under Cross-site Scripting. CVSS score: 8.9/10. Published 2026-05-08.

How severe is CVE-2026-42556?

High severity. CVSS v3 base score is 8.9 out of 10.

XSS in Gitroom Postiz

CVE-2026-42556

Postiz is an AI social media scheduling tool. From version 2.21.6 to before version 2.21.7, any authenticated user who can create a post can store arbitrary HTML in post content by tampering their own save request and send the public previ…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.000 (13.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.9 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:L.

Affected products

Gitroom Postiz — versions 2.21.6
Gitroomhq Postiz-app — versions >= 2.21.6, < 2.21.7

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
security-advisories@github.com (Product, x_refsource_MISC, Release Notes)

Frequently asked questions

What is CVE-2026-42556?: CVE-2026-42556 is a high-severity vulnerability in Gitroom Postiz, classified under Cross-site Scripting. CVSS score: 8.9/10. Published 2026-05-08.
How severe is CVE-2026-42556?: High severity. CVSS v3 base score is 8.9 out of 10.