Remote code execution in Elo Ruby backend via unescaped interpolation
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-1336.
Summary
Elo, a purely functional expression language for no-code tools, is affected before 1.0.1 in its Ruby backend. The Ruby emitter does not escape # in attacker-controlled text placed in double-quoted Ruby strings, so Ruby interpolation becomes executable. An attacker who can supply expressions can run Ruby code and shell commands through backticks when the compiled Ruby runs, without authentication. JavaScript, Python and SQL emission are not affected.
Written with Claude Haiku 5.5 from the sources below · 2026-11-03
Description from the CNA
Elo is a purely functional expression language for no-code tools. Prior to 1.0.1, the Ruby backend in src/compilers/ruby.ts embeds attacker-controlled text in Ruby double-quoted strings without escaping #, so Ruby interpolation forms in the string-literal emitter or the labelled subtype-constraint branch become executable Ruby. The affected entry points include the /try playground with the Ruby target, bin/eloc -t ruby -x, and defaultFormats.elo.parse() followed by Ruby emission. A failing labelled subtype constraint evaluates its message, while an ordinary string literal is evaluated when the compiled Ruby runs, allowing Ruby code and shell command execution through backticks. JavaScript, Python, and SQL emission are not affected by this Ruby-specific path. This issue is fixed in version 1.0.1.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| enspirit | elo | before 1.0.1 | 1.0.1 | Patch available | CNA |
| — | @enspirit/elo (npm) | before 1.0.1 | 1.0.1 | Patch available | GHSA-7w38-ggh5-v542 |
- elo Vendorenspirit Affected before 1.0.1 Fixed in 1.0.1 Patch available CNA
- @enspirit/elo (npm) Vendor— Affected before 1.0.1 Fixed in 1.0.1 Patch available GHSA-7w38-ggh5-v542
Remediation
Update enspirit elo and the npm package @enspirit/elo to version 1.0.1, which fixes the issue.
Written with Claude Haiku 5.5 from the sources below · 2026-11-03
- Fix · CNA elo (enspirit) Fixed in 1.0.1
- Fix · GHSA-7w38-ggh5-v542 @enspirit/elo (npm) Fixed in 1.0.1 Advisory →
Timeline
- 2026-11-03 Threatist record created from CVE-2026-44266
- 2026-11-03 Alias added: GHSA-7w38-ggh5-v542
- 2026-11-03 Fix available: npm/@enspirit/[email protected] · GHSA-7w38-ggh5-v542
- 2026-11-03 CVSS score added · GHSA-7w38-ggh5-v542
- 2026-11-03 Weakness changed · GHSA-7w38-ggh5-v542
- 2026-11-03 4 new references · GHSA-7w38-ggh5-v542
- 2026-11-03 CISA SSVC decision points changed
- 2026-11-03 Priority changed: MEDIUM → HIGH
References
More enspirit vulnerabilities
- TI-2026-84456 Sandbox escape in Elo JavaScript emitter allows arbitrary code execution CVSS 3.1CRITICAL 9.8
- TI-2026-84454 Code injection in Elo via unvalidated programmatic AST fields CVSS 3.1HIGH 7.4
Sources
- CVE-2026-44266 · CVE Program
- CVE-2026-44266 · NVD
- FIRST EPSS
- GHSA-7w38-ggh5-v542 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences