Answer in brief
CVE-2026-122131 records a Medium severity (CVSS 6.3) vulnerability in Joi 17.13.6 before 17.13.9 and 18.2.5 before 18.3.1 Prototype Replacement via __proto__ Language Key. The current sources do not mark it as known exploited. The current feed maps hapijs/joi (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps hapijs/joi (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| hapijs/joigeneric | >=17.13.6 <17.13.9 || >=18.2.5 <18.3.1 | 17.13.9, 18.3.1 |
Published upstream
Nov 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 4, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 4, 2026
Joi 17.13.6 before 17.13.9 and 18.2.5 before 18.3.1 contains a prototype pollution vulnerability in lib/messages.js compile() and merge() that fails to reject a __proto__ language key. Attackers supplying untrusted message configuration via any().messages(), prefs, validate options or Joi.extend can replace the compiled messages prototype, altering or breaking validation error rendering and dependent logic.
Quoted source text, attributed separately from HOL analysis.