CVE-2026-33386 | QuickCMS is vulnerable to Cross-Site Scripting (XSS) through… | CVSS 2.3 LOW

Description

QuickCMS is vulnerable to Cross-Site Scripting (XSS) through its insecure HTTP-based plugin‑fetching mechanism. A malicious attacker can perform a Man‑in‑the‑Middle (MITM) attack by impersonating the opensolution.org server and serving arbitrary HTML or JavaScript at the plugin list endpoint. When a user accesses the plugin page, the malicious content is automatically fetched, rendered, and executed. This issue was fixed in a patch to version 6.8 published on 15.05.2026, deployments without this patch are still vulnerable.

Metadata

CVE ID: CVE-2026-33386
State: PUBLISHED
Assigner: CERT-PL
Reserved: 2026-03-19 10:45 UTC
Published: 2026-05-29 15:12 UTC
Last updated: 2026-05-29 17:31 UTC
Primary CWE: CWE-79
CWE-79 Improper Neutralization of Input During Web Page Gene…
Vendor / Product: OpenSolution / QuickCMS
Sources: cve.org · NVD

Severity & Metrics

2.3 LOW CVSS 4.0

CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
OpenSolution	QuickCMS	—	0 ≤ 6.8

Weakness (CWE)

CWE	Source	Description
CWE-79	cna	CWE-79 Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting')

CVSS scores (1)

Score	Severity	Version	Source	Vector
2.3	LOW	4.0	cna	CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

References (2)