Answer in brief
CVE-2026-86258 records a High severity (CVSS 8.2) vulnerability in nbviewer through 1.0.1 Path Traversal via LocalFileHandler. The current sources do not mark it as known exploited. The current feed maps jupyter/nbviewer (generic), jupyter/nbviewer (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 8.2. 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 jupyter/nbviewer (generic), jupyter/nbviewer (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| jupyter/nbviewergeneric | 0 | Not reported |
| jupyter/nbviewergeneric | >=0 <=1.0.1 | Not reported |
Published upstream
Sep 6, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 6, 2026
nbviewer through 1.0.1 contains a path traversal vulnerability in LocalFileHandler.can_show() that uses string-prefix comparison instead of proper path validation. Attackers can read files from sibling directories outside the configured root by requesting paths that share the root as a textual prefix, disclosing unintended notebooks and credentials.
Quoted source text, attributed separately from HOL analysis.