CVE-2026-42084: OpenC3 COSMOS: Hijacked session token can be used to reset password for persistence
(updated )
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.
References
- github.com/OpenC3/cosmos/commit/2e623714e3426d5ae81b6f8239d4a2a6937ef776
- github.com/OpenC3/cosmos/releases/tag/v6.10.5
- github.com/OpenC3/cosmos/releases/tag/v7.0.0-rc3
- github.com/OpenC3/cosmos/security/advisories/GHSA-wgx6-g857-jjf7
- github.com/advisories/GHSA-wgx6-g857-jjf7
- github.com/rubysec/ruby-advisory-db/blob/master/gems/openc3/CVE-2026-42084.yml
- nvd.nist.gov/vuln/detail/CVE-2026-42084
Code Behaviors & Features
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