CVE-2026-126210 (CVSS 5.3)

Description

@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.

Is your site exposed to CVE-2026-126210?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.3

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Weakness Type (CWE)

CWE-436 CWE-436

References

Other References

https://github.com/honojs/node-server/commit/3868998a805ae79216535ad3986c1e7228dee313 https://github.com/honojs/node-server/commit/fb97395ec36af66567c76976e741110b02804d1c https://github.com/honojs/node-server/releases/tag/v1.19.18 https://github.com/honojs/node-server/releases/tag/v2.1.6 https://github.com/honojs/node-server/security/advisories/GHSA-jpvv-r467-5p4w

Frequently Asked Questions

What is CVE-2026-126210? +

@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. It has a CVSS v3.1 base score of 5.3 (MEDIUM).

How severe is CVE-2026-126210? +

CVE-2026-126210 has a CVSS v3.1 score of 5.3 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

How do I check if I'm vulnerable to CVE-2026-126210? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-42273

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall performs host …

CVE-2026-47344

When ALLOW_INSECURE_RAW_TEXT is enabled, whitespace-variant closing tags (e.g., </style\t>) are not recognized by the sanitizer but accepted by browsers as …

CVE-2026-115700

Interpretation Conflict vulnerability in hackney_url in benoitc hackney allows Server Side Request Forgery via a percent-encoded bracketed IPv6 literal or …

CVE-2026-44974

@hapi/content provided HTTP Content-* headers parsing. Prior to 6.0.2, Content.disposition() retained the last occurrence of each duplicate parameter while Content.type() …

CVE-2026-42274

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall performs rule …

CVE-2025-54368

uv is a Python package and project manager written in Rust. In versions 0.8.5 and earlier, remote ZIP archives were …