Answer in brief
CVE-2026-63462 records a High severity (CVSS 7.5) vulnerability in Unleash: Unauthenticated single-request DoS via OpenAPI validation error formatter. The current sources do not mark it as known exploited. The current feed maps Unleash/unleash (generic), unleash-server (npm), unleash-server (npm), unleash-server (npm). 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 7.5. 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 Unleash/unleash (generic), unleash-server (npm), unleash-server (npm), unleash-server (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Unleash/unleashgeneric | < 7.5.2 || >= 7.6.0, < 7.6.5 || >= 8.0.0, < 8.0.2 | Not reported |
| unleash-servernpm | <7.5.2 | 7.5.2 |
| unleash-servernpm | >=7.6.0,<7.6.5 | 7.6.5 |
| unleash-servernpm | >=8.0.0,<8.0.2 | 8.0.2 |
Published upstream
Aug 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 21, 2026
Unleash is an open-source feature management platform. Prior to 7.5.2, 7.6.5, and 8.0.2, the shared OpenAPI validation error path in src/lib/error/bad-data-error.ts passes a raw request value from lodash.get to JSON.stringify in genericErrorMessage and fromOpenApiValidationErrors without guarding stack exhaustion. An unauthenticated attacker can send a roughly 10 KB JSON value nested thousands of levels deep to POST /edge/validate, POST /edge/issue-token, or another OpenAPI-validated endpoint, causing RangeError: Maximum call stack size exceeded in openAPIValidationMiddleware and terminating the Node process because no uncaughtException handler recovers it. Replaying the request can sustain a complete service outage. This issue is fixed in versions 7.5.2, 7.6.5, and 8.0.2.
Quoted source text, attributed separately from HOL analysis.