CVE-2026-33386
CVE-2026-33386 is a low-severity vulnerability with a CVSS 4.0 base score of 2.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.
Key facts
- Severity: Low (CVSS 4.0 base score 2.3)
- EPSS exploit prediction: 0% (8th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-33339
- Weakness: CWE-79
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-33386?
- 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.
- How severe is CVE-2026-33386?
- CVE-2026-33386 has a CVSS 4.0 base score of 2.3, rated low severity.
- Is CVE-2026-33386 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (8th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-33386?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2026-33386 have an EU (EUVD) identifier?
- Yes. CVE-2026-33386 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33339.
- When was CVE-2026-33386 published?
- CVE-2026-33386 was published on 2026-05-29 and last updated on 2026-06-17.
References
Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities
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