Vulnerability in Openc3 Cosmos
CVE-2026-42084
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.003 (23.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 23.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
- Openc3 Cosmos — versions < 6.10.5, 7.0.0, >= 7.0.0.pre.rc1, < 7.0.0-rc3
Weakness classification (CWE)
References
- github.com/OpenC3/cosmos/security/advisories/GHSA-wgx6-g857-jjf7 (Exploit, Vendor Advisory)
- github.com/OpenC3/cosmos/commit/2e623714e3426d5ae81b6f8239d4a2a6937ef776 (Patch)
- github.com/OpenC3/cosmos/releases/tag/v6.10.5 (Release Notes)
- github.com/OpenC3/cosmos/releases/tag/v7.0.0-rc3 (Release Notes)
Frequently asked questions
- What is CVE-2026-42084?
- CVE-2026-42084 is a high-severity vulnerability in Openc3 Cosmos, classified under CWE-620. CVSS score: 8.1/10. Published 2026-05-04.
- How severe is CVE-2026-42084?
- High severity. CVSS v3 base score is 8.1 out of 10.