CVE-2026-42084: OpenC3 COSMOS: Hijacked session token can be used to reset password for persistence
OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. Prior to versions 6.10.5 and 7.0.0-rc3, the OpenC3 password change functionality allows a user to change their password without providing the old password, by accepting a valid session token instead. In assumed breach scenarios, this behaviour can be exploited by an attacker who has already obtained a valid session token, to gain persistence in hijacked account (including admin) and prevent legitimate users from accessing the account. This issue has been patched in versions 6.10.5 and 7.0.0-rc3.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-42084?
The severity of CVE-2026-42084 is considered high due to the potential for unauthorized password resets via hijacked session tokens.
How do I fix CVE-2026-42084?
To fix CVE-2026-42084, upgrade OpenC3 COSMOS to versions 6.10.5 or later, or 7.0.0-rc3 or later.
What versions of OpenC3 COSMOS are affected by CVE-2026-42084?
CVE-2026-42084 affects OpenC3 COSMOS versions prior to 6.10.5 and 7.0.0-rc3.
What type of vulnerability is CVE-2026-42084?
CVE-2026-42084 is a session hijacking vulnerability that allows attackers to reset user passwords.
Who is impacted by CVE-2026-42084?
Users of OpenC3 COSMOS prior to the fixed versions are impacted by CVE-2026-42084.