Verification Bypass in jsonwebtoken

Answer in brief

CVE-2015-9235 records a Unknown severity vulnerability in Verification Bypass in jsonwebtoken. The current sources do not mark it as known exploited. The current feed maps jsonwebtoken (npm). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 9, 2018Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Aug 7, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

A CVSS score is not reported in the current record. 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.

Affected scope and exposure questions

The current feed maps jsonwebtoken (npm). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
jsonwebtokennpm	>=0 <4.2.2	4.2.2

Recommended response

Check inventory. Check lockfiles and deployed manifests for jsonwebtoken.
Review the reported fix. Update jsonwebtoken to 4.2.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Oct 9, 2018
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Aug 7, 2026

Sources and claim methodology

Upstream source description

Versions 4.2.1 and earlier of `jsonwebtoken` are affected by a verification bypass vulnerability. This is a result of weak validation of the JWT algorithm type, occuring when an attacker is allowed to arbitrarily specify the JWT algorithm. ## Recommendation Update to version 4.2.2 or later.

Quoted source text, attributed separately from HOL analysis.