❌

Normal view

CVE-2026-84115 in Cleo Harmony: JWT Refresh Token Handler Flaw Exposes Remote Attack Risk

3 September 2026 at 05:27

CVE-2026-84115

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 endpoint. Β  MITRE documented the issue on September 1, 2026, while VulDB classified it as a serious privilege-management vulnerability with a CVSS score of 8.3.Β 

CVE-2026-84115 Targets JWT Refresh Token HandlerΒ 

According to the vulnerability analysis, CVE-2026-84115 involves an unknown function within the JWT Refresh Token Handler component. The affected functionality processes requests sent to /api/connections, where manipulation of the Bearer argument in HTTP authorization headers can lead to improper privilege management.Β  The weakness is classified as CWE-269, which refers to Improper Privilege Management. The flaw can allow an attacker to manipulate authentication-token arguments and potentially bypass intended access controls, gaining privileges beyond those assigned to the account.Β 

Remote Exploitation Raises CVE-2026-84115 RiskΒ 

The vulnerability is remotely exploitable because the attack can be conducted through network-based HTTP requests without requiring local or physical access to the targeted system. The risk is heightened because a public exploit has reportedly been made available.Β  An attacker exploiting CVE-2026-84115 could potentially obtain unauthorized administrative access, view sensitive information stored within Harmony, or interfere with integration workflows managed through the platform. Such activity could affect the confidentiality, integrity, and availability of systems that depend on Cleo Harmony for file transfer and API connectivity.Β  The VulDB analysis links the exploitation method to authentication bypass through token manipulation. Attackers could potentially intercept legitimate traffic or create forged requests using malformed or replayed bearer tokens to circumvent JWT refresh-token controls. In environments where Cleo Harmony is connected to other systems, successful exploitation could also provide opportunities for further lateral movement.Β 

CVE-2026-84115 Remediation Requires an UpgradeΒ 

Organizations using affected Cleo Harmony versions should upgrade to version 5.8.1.11 or later. The release contains the necessary correction for the privilege-management problem affecting the JWT Refresh Token Handler.Β  Until patching is possible, organizations can strengthen input validation on API endpoints and monitor for unusual patterns involving bearer tokens. These measures may improve detection and reduce exposure, but they do not replace the recommended software upgrade, particularly given the reported public exploit.Β  VulDB is listed as the responsible organization, with the vulnerability recorded under VDB-397558. Disclosure took place on September 1, 2026, and the entry has an accepted moderation status, with CPE marked as ready. CWE-269 is confirmed for the vulnerability. VulDB assigns CVE-2026-84115 a CVSS score of 8.3 and an EPSS score of 0.00284. The vulnerability record also identifies an exploit as available for download.

SonicWall Warns of Two Actively Exploited SMA1000 Zero-Days, One Rated Maximum Severity

3 September 2026 at 03:47

Graphic showing SonicWall SMA1000 devices, CVE-2026-83548, the maximum-severity SonicWall SMA1000 pre-authentication vulnerability

SonicWall disclosed this week that attackers are chaining two previously unknown vulnerabilities in its SMA1000 secure access appliances to run commands on unpatched devices, and urged customers to install an emergency hotfix.

The more severe flaw, CVE-2026-83548, is a pre-authentication server-side request forgery weakness in the appliance's Appliance Work Place interface, rated 10.0 on the CVSS scale. It lets a remote attacker with no credentials reach sensitive internal functionality. The second, CVE-2026-83549, is an operating-system command injection bug in the Appliance Management Console rated 7.8; on its own it requires administrative authentication, but paired with the SSRF flaw it yields remote code execution.

The vendor said it found both issues internally and then observed them being used together in live attacks. SonicWall has not published indicators of compromise or described the attackers.

Affected products are the SMA1000 series 6210, 7210 and 8200v, in both hardware and virtual form. Fixed builds are 12.4.3-03526 and later, and 12.5.0-02952 and later. SonicWall firewalls running SSL-VPN and the separate SMA 100 line are not affected.

Remediation guidance goes beyond patching. SonicWall told customers to contact its support organization to review appliances for signs of intrusion and, where compromise is suspected, to re-image or redeploy the device, rotate all credentials and reset TOTP tokens β€” an acknowledgment that one-time-password seeds stored on a breached appliance survive a software update. The company said customers should move to the hotfix release as quickly as possible.

Shadowserver Foundation scanning has tracked more than 400 internet-exposed SMA1000 appliances, though an unknown share of those are already patched. The small install base belies the risk profile. These are remote-access gateways that sit at the network edge and hold credentials for the environments behind them.

The disclosure extends a difficult run for the product line. Attackers exploited a separate pair of SMA1000 zero-days in July 2026, tracked as CVE-2026-15409 and CVE-2026-15410, to deploy custom malware; CISA later confirmed ransomware operators were abusing that access.

Read: CISA Adds SonicWall SMA1000 Vulnerabilities to KEV Catalog Following Active Exploitation

Another zero-day surfaced in December 2025. Seventeen SonicWall vulnerabilities across the company's product families currently sit in CISA's Known Exploited Vulnerabilities catalog. Edge appliances from SonicWall, Ivanti, Citrix and Fortinet have collectively become the preferred initial-access route for ransomware affiliates and espionage crews, because they are internet-facing by design and rarely instrumented with endpoint detection.

❌