Vulnerability in openc3 (CVE-2026-42085)
Summary
Vulnerability in openc3 (CVE-2026-42085). Risk of unauthorized operations or information disclosure. Exploitable via OPENC3_LOCAL_MODE_PATH. Mitigation: upgrade to 7.0.0-rc3 or later.
Original description
The description as published by the source.
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, OpenC3 COSMOS contains a design flaw in the save_tool_config() function that allows saving tool configuration files at arbitrary locations inside the shared /plugins directory tree by supplying crafted configuration filenames. Although the implementation sufficiently mitigates standard path traversal attacks, by canonicalizing filename to an absolute path, all plugins share this same root directory. That enables users to create arbitrary file structures and overwrite existing configuration files within the shared /plugins directory. This issue has been patched in versions 6.10.5 and 7.0.0-rc3.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-42085 has been found in openc3.
Attackers can target a specific entry point like OPENC3_LOCAL_MODE_PATH over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 4.3/10.
What to do: upgrade openc3 to 7.0.0-rc3 or later.
If unsure, ask your IT team or search "openc3 CVE-2026-42085" on the vendor's site.
CVE-2026-42085 (openc3) — CWE-23 / CVSS v3 4.3
Attack vector: remote (network-reachable) / no user interaction
Attack surface: OPENC3_LOCAL_MODE_PATH / plugin_default
Patched: 7.0.0-rc3 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-23) exists in openc3. Attackers reach the vulnerable code path via OPENC3_LOCAL_MODE_PATH.
Check the vendor advisory for the affected versions of openc3. Attack surface: OPENC3_LOCAL_MODE_PATH / plugin_default.
Severity: Medium (CVSS 4.3/10). Risk of unauthorized operations or information disclosure.
Update to 7.0.0-rc3.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'openc3' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
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1Identify exposure identify
grep -r 'openc3' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
openc3を grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade openc3 to 7.0.0-rc3ステージング環境で 7.0.0-rc3 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory github.com
- advisory nvd.nist.gov
- advisory github.com
- package github.com
- patch github.com
- patch github.com
- web github.com
- web github.com
- web github.com
- web github.com