Vulnerability · Published May 4, 2026 · Assigned by GitHub_M
CVE-2026-42084OpenC3 COSMOS: Hijacked session token can be used to reset password for persistence
High 8.1
In plain English
A high-severity security flaw in cosmos from OpenC3. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | openc3 | 6.10.5 | PYSEC-2026-2242 |
| RubyGems | openc3 | 6.10.5 | GHSA-wgx6-g857-jjf7 |
| RubyGems | openc3 | 7.0.0-rc3 | GHSA-wgx6-g857-jjf7 |
Affected products (as reported)
Weakness: CWE-620 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
References
- https://github.com/OpenC3/cosmos/security/advisories/GHSA-wgx6-g857-jjf7 x_refsource_CONFIRM
- https://github.com/OpenC3/cosmos/commit/2e623714e3426d5ae81b6f8239d4a2a6937ef776 x_refsource_MISC
- https://github.com/OpenC3/cosmos/releases/tag/v6.10.5 x_refsource_MISC
- https://github.com/OpenC3/cosmos/releases/tag/v7.0.0-rc3 x_refsource_MISC