CVE-2026-84115
Cleo Harmony JWT Refresh Token connections privileges management
Description
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.
INFO
Published Date :
Sept. 1, 2026, 3:17 p.m.
Last Modified :
Sept. 1, 2026, 8:47 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 2.0 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Upgrade Cleo Harmony to version 5.8.1.11.
- Apply available updates for the JWT Refresh Token Handler.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-84115.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-84115 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-84115
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-84115 vulnerability anywhere in the article.
-
The Cyber Express
Attackers Exploit Unpatched Magento Zero-Day to Backdoor Online Stores
Attackers are exploiting an unpatched remote code execution flaw in Adobe Commerce and Magento Open Source to install persistent backdoors on e-commerce sites, Dutch security firm Sansec reported, wit ... Read more
-
The Cyber Express
Attackers Exploited MikroTik RouterOS Flaws a Day Before Patches Shipped
Attackers began compromising internet-exposed MikroTik routers on Sept. 2, a day before the Latvian vendor released fixes and three days before national authorities published the technical detail defe ... Read more
-
The Cyber Express
Liquid Network Hackers Demand Bug Fix Before Returning $320M BTC
The Liquid Network security incident has taken an unusual turn after the unidentified actors behind the theft of nearly 4,000 BTC offered to return “most” of the funds — but only after the vulnerabili ... Read more
-
The Cyber Express
The Cyber Express Weekly Roundup: Claude Session Hijacking, PaperCut Exploits, and Enterprise Cyberattacks
This weekly roundup highlights a range of cybersecurity developments affecting artificial intelligence platforms, enterprise software, healthcare organizations, social media accounts, and internet-fac ... Read more
-
The Cyber Express
Two Citrix NetScaler Flaws Put Enterprise Edge Devices at Risk
Two Citrix NetScaler vulnerabilities affecting Citrix NetScaler Application Delivery Controller (ADC) and Citrix NetScaler Gateway products have prompted a patching warning for Australian organisation ... Read more
-
The Cyber Express
CVE-2026-84115 in Cleo Harmony: JWT Refresh Token Handler Flaw Exposes Remote Attack Risk
A critical vulnerability identified as CVE-2026-84115 affects Cleo Harmony versions through 5.8.1.10, with the weakness tied to the platform’s JWT Refresh Token Handler and the /api/connections endpoi ... Read more
The following table lists the changes that have been made to the
CVE-2026-84115 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Sep. 01, 2026
Action Type Old Value New Value Added Reference https://vuldb.com/submit/882468 Added SSVC {'id': 'CVE-2026-84115', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-09-01T15:58:17.546452Z'} -
New CVE Received by [email protected]
Sep. 01, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:L/SI:L/SA:L/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:L Added CVSS V2 (AV:N/AC:L/Au:N/C:P/I:P/A:P) Added CWE CWE-266 Added CWE CWE-269 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/84xxx/CVE-2026-84115.json">CVE-2026-84115</a> Added Reference https://support.cleo.com/hc/en-us/articles/30258468834583-Cleo-Harmony-5-8-1-Release-Notes#Version58111 Added Reference https://vuldb.com/cve/CVE-2026-84115 Added Reference https://vuldb.com/submit/882468 Added Reference https://vuldb.com/vuln/397558 Added Reference https://vuldb.com/vuln/397558/cti