---
title: "CVE-2026-42087: OpenC3 COSMOS has SQL Injection in QuestDB Time-Series Database"
url: https://erroneo.us/security/cve/CVE-2026-42087/
description: "CVE-2026-42087 (openc3 (RubyGems)): OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems.…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-05-04
date_modified: 2026-05-29
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-42087"
kev: false
cvss: 9.6
epss: 0.00445
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-42087: OpenC3 COSMOS has SQL Injection in QuestDB Time-Series Database

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Not in CISA KEV , but CISA’s SSVC assessment records a public proof-of-concept, so attack code exists.
- EPSS 0.4% , percentile 38: FIRST’s model estimates a 0.4% chance of exploitation activity in the next 30 days, higher than 38% of all scored CVEs (low). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes openc3 (RubyGems) >= 6.7.0, < 7.0.0-rc3, fixed in 7.0.0-rc3 . Check your lockfile, including transitive dependencies.

## What it is

OpenC3 COSMOS provides the functionality needed to send commands to and receive data from one or more embedded systems. From version 6.7.0 to before version 7.0.0-rc3, a SQL injection vulnerability exists in the Time-Series Database (TSDB) component of COSMOS. The tsdblookup function in the cvtmodel.rb file directly places user-supplied input into a SQL query without sanitizing the input. As a result, a user can break out of the initial SQL statement and execute arbitrary SQL commands, including deleting data. This issue has been patched in version 7.0.0-rc3.

## Affected packages

- RubyGems `openc3` >= 6.7.0, < 7.0.0-rc3 → fixed: 7.0.0-rc3

## Affected products (CVE record)

- OpenC3 cosmos: >= 6.7.0, < 7.0.0-rc3

## Severity

- GitHub_M CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`
- GitHub CVSS 3.1: 9.6 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation poc , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 0.45% probability of exploitation activity in the next 30 days; percentile 38.

## Sources

- [GitHub Advisory GHSA-v529-vhwc-wfc5](https://github.com/advisories/GHSA-v529-vhwc-wfc5)
- [CVE.org record CVE-2026-42087](https://www.cve.org/CVERecord?id=CVE-2026-42087)
- [NVD entry CVE-2026-42087](https://nvd.nist.gov/vuln/detail/CVE-2026-42087)
- [github.com](https://github.com/OpenC3/cosmos/security/advisories/GHSA-v529-vhwc-wfc5)
- [github.com](https://github.com/OpenC3/cosmos/commit/9ba60c09c8836a37a2e4ea67ab35fe403e041415)
- [github.com](https://github.com/OpenC3/cosmos/releases/tag/v7.0.0-rc3)
- [github.com](https://github.com/rubysec/ruby-advisory-db/blob/master/gems/openc3/CVE-2026-42087.yml)

---
Source page: https://erroneo.us/security/cve/CVE-2026-42087/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt