Privilege escalation in Cleo Harmony
CVE-2026-84115
A vulnerability was found in Cleo Harmony up to 5.8.1.10. The affected element is an unknown function of the file /api/connections of the component JWT Refresh Token Handler. Performing a manipulation of the argument Bearer results in improper privilege management. The attack is possible to be carried out remotely. The exploit has been made public and could be used. Upgrading to version 5.8.1.11 is sufficient to fix this issue. It is recommended to upgrade the affected component.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.005 (39.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 39.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002
Affected products
- Cleo Harmony — versions 5.8.1.0, 5.8.1.1, 5.8.1.10
Weakness classification (CWE)
References
- support.cleo.com/hc/en-us/articles/30258468834583-Cleo-Harmony-5-8-1-Release-No… (patch, broken-link)
- vuldb.com/cve/CVE-2026-84115 (third-party-advisory)
- vuldb.com/submit/882468 (third-party-advisory)
- vuldb.com/vuln/397558 (technical-description, vdb-entry)
- vuldb.com/vuln/397558/cti (signature, permissions-required)
Frequently asked questions
- What is CVE-2026-84115?
- CVE-2026-84115 is a high-severity vulnerability in Cleo Harmony, classified under Incorrect Privilege Assignment. CVSS score: 8.3/10. Published 2026-09-01.
- How severe is CVE-2026-84115?
- High severity. CVSS v3 base score is 8.3 out of 10.