CVE-2026-77602OpenC3 COSMOS: Authenticated remote code execution via the user-writable config overlay (table definitions, cmd/tlm definitions, and script suites)
- 9.9CriticalCVSS base score
- 0.72%Exploitation in 30 daysEPSS · top 46% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- YesPublic exploitsa reference or SSVC says so
Description
OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. From 5.1.0 until 7.3.0, authenticated non-administrator users can write content under targets_modified/ that is later executed by multiple configuration paths below the intended code-execution privilege tier. Table and command or telemetry definitions are processed through ConfigParser, PacketConfig, GENERIC_READ_CONVERSION, or GENERIC_WRITE_CONVERSION, allowing ERB rendering or Ruby and Python evaluation, while openc3-cosmos-script-runner-api/scripts/run_suite_analysis.rb executes suite procedure files through require. Storage uploads, screen saves, and script creation can place content in the overlay, and triggering table processing, a cmd/tlm reload, or suite analysis executes the content in cmd-tlm-api, decom microservices, or Script Runner with access to internal credentials and data. This issue is fixed in version 7.3.0.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. A reference of the record is tagged as an exploit. CISA's SSVC rates its exploitation: a proof of concept is public.
Show the exploits1
References tagged exploit1 reference
- https://github.com/OpenC3/cosmos/security/advisories/GHSA-jjq7-m736-w977 (opens in a new tab)x_refsource_CONFIRMexploit
Timeline
ID reserved
By GitHub_M
- 34 days later
· 34 days later
Published
- 6 days later
· 6 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | Critical9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Deferred | 3.1 | Critical9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.72% · top 46% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.9.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemsopenc3GHSA-jjq7-m736-w977 (opens in a new tab)
References
References4
- https://github.com/OpenC3/cosmos/security/advisories/GHSA-jjq7-m736-w977 (opens in a new tab)x_refsource_CONFIRMexploit
- https://github.com/OpenC3/cosmos/pull/3488 (opens in a new tab)x_refsource_MISC
- https://github.com/OpenC3/cosmos/commit/71943352a28128ef3e7e894319d97a656b5cd4f2 (opens in a new tab)x_refsource_MISC
- https://github.com/OpenC3/cosmos/commit/7a1538a4626f82c0d1540fcaa27ffdcbbd71ff81 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-85566 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-jjq7-m736-w977 (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-77602)Record last updated .