CVE-2026-77602

CRITICALPre-NVD 9.99.9—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6% (45th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Elevated
9.9EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.6%CVSS: 9.9Exploit: Elevated riskExposed services: Not assessed

A fix is available — apply it.

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.

CVSS v3
9.9
EG Score
9.9CRITICALmedium confidence
EG Risk
61
EG Risk 61/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity99% × 45%
Exploitation40% × 40%
Automatability0% × 15%
CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.6%
EPSS %ILE
45th
KEV
Not listed

CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

September 23, 2026

Last Modified

September 29, 2026

Advisory Details (4)

Auto-updated Sep 29, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_pr, github.
github Patch Available🟡 PoC Available

Authenticated remote code execution via the user-writable config overlay (table definitions, cmd/tlm definitions, and script suites) · Advisory · OpenC3/cosmos · GitHub

https://github.com/OpenC3/cosmos/security/advisories/GHSA-jjq7-m736-w977
github_pr

Treat targets_modified overlay as data, not code

Fix merged in OpenC3/cosmos PR #3488 on 2026-07-02 — awaiting tagged release

https://github.com/OpenC3/cosmos/pull/3488
github_commit

commit 7a1538a4626f (OpenC3/cosmos)

Fix landed in OpenC3/cosmos commit 7a1538a4626f — awaiting tagged release

https://github.com/OpenC3/cosmos/commit/7a1538a4626f82c0d1540fcaa27ffdcbbd71ff81
github_commit

commit 71943352a281 (OpenC3/cosmos)

Fix landed in OpenC3/cosmos commit 71943352a281 — awaiting tagged release

https://github.com/OpenC3/cosmos/commit/71943352a28128ef3e7e894319d97a656b5cd4f2

Vendor Advisories for CVE-2026-77602(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Affected Packages

(1 across 1 ecosystem)
RubyGems(1)
PackageVulnerable rangeFixed inDependents
openc35.1.0 ... 7.2.1 (78 versions)7.3.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 15× in last 7d / 24× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-03 15:50 UTCEG score recompute
  2. 2026-10-03 14:26 UTCEPSS rescore
  3. 2026-10-02 19:39 UTCEG score recompute
  4. 2026-10-01 19:58 UTCEG score recompute
  5. 2026-10-01 19:50 UTCEPSS rescore
  6. 2026-09-30 16:38 UTCEG score recompute
  7. 2026-09-29 19:13 UTCEG score recompute
  8. 2026-09-29 15:24 UTCEPSS rescore
  9. 2026-09-29 03:33 UTCEG score recompute
  10. 2026-09-29 02:36 UTCEG score recompute
  11. 2026-09-28 22:11 UTCEG score recompute
  12. 2026-09-28 18:14 UTCEG score recompute
  13. 2026-09-28 13:52 UTCEPSS rescore
  14. 2026-09-27 14:21 UTCEG score recompute
  15. 2026-09-27 13:48 UTCEPSS rescore
  16. 2026-09-26 18:39 UTCEG score recompute
  17. 2026-09-26 15:59 UTCEPSS rescore
  18. 2026-09-26 03:02 UTCEG score recompute
  19. 2026-09-26 00:28 UTCEPSS rescore
  20. 2026-09-24 15:03 UTCEG score recompute
  21. 2026-09-24 14:04 UTCEPSS rescore
  22. 2026-09-23 19:26 UTCEG score recompute
  23. 2026-09-23 19:04 UTCEG score recompute
  24. 2026-09-23 19:04 UTCMITRE cvelistV5first tracked

Related CVEs(same product + same CWE)

Frequently asked(5)

What is CVE-2026-77602?
CVE-2026-77602 is a critical vulnerability published on September 23, 2026. 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 targetsmodified/ that is later executed by multiple configuration paths below the intended…
When was CVE-2026-77602 disclosed?
CVE-2026-77602 was first published on September 23, 2026, with the most recent update on September 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-77602 actively exploited?
CVE-2026-77602 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.6% probability of exploitation in the next 30 days (45th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-77602?
CVE-2026-77602 has a CVSS base score of 9.9 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-77602?
A fix for CVE-2026-77602 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-77602 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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