Answer in brief
CVE-2026-126210 records a Medium severity (CVSS 5.3) vulnerability in @hono/node-server: Backslash in the request path is parsed as a path separator, bypassing path-based access control at a reverse proxy. The current sources do not mark it as known exploited. The current feed maps honojs/node-server (generic), @hono/node-server (npm), @hono/node-server (npm), @hono/node-server (npm) and additional mapped packages. 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 5.3. 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 honojs/node-server (generic), @hono/node-server (npm), @hono/node-server (npm), @hono/node-server (npm) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| honojs/node-servergeneric | >=2.0.0 <2.1.6 || <1.19.18 | 1.19.18, 2.1.6 |
| @hono/node-servernpm | >=2.0.0,<2.1.6 | 2.1.6 |
| @hono/node-servernpm | <1.19.18 | 1.19.18 |
| @hono/node-servernpm | >=2.0.0,<2.1.6 | 2.1.6 |
| @hono/node-servernpm | <1.19.18 | 1.19.18 |
Published upstream
Nov 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 12, 2026
@hono/node-server allows running the Hono application on Node.js. Prior to 1.19.18 and from 2.0.0 until 2.1.6, the server passes a raw request-target containing a backslash in its path to the WHATWG URL parser, which treats the backslash as a path separator and resolves dot segments. A reverse proxy, load balancer, or web application firewall that preserves the backslash and applies path-based rules to the original request can therefore permit a request that the application normalizes to a blocked route. This lets an unauthenticated client reach route content that the upstream component was intended to deny, while Hono application access controls are unaffected because they operate on the normalized path. This issue is fixed in versions 1.19.18 and 2.1.6.
Quoted source text, attributed separately from HOL analysis.