TI-2026-48551 Aliases CVE-2026-69207 GHSA-8j4g-w8fx-2239

Hono: ReDoS in CORS middleware via Access-Control-Request-Headers

LOW 25CWE-1333Published 2026-08-07 · Updated 2026-08-10

Key facts

Attack vector: Network
Privileges required: None
User interaction: None
Attack complexity: Low
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · Low
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-1333.

Summary

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.34, the built-in CORS middleware, hono/cors, is vulnerable to a regular expression denial of service (ReDoS). During a preflight OPTIONS request, the middleware parses the attacker-controlled Access-Control-Request-Headers header using a whitespace-tolerant regular expression whose backtracking makes its running time quadratic in the input length. Because the header value is bounded only by the deployment's maximum HTTP header size, a single preflight carrying a long run of whitespace can consume seconds of CPU and block request processing. On runtimes that share one execution thread across requests, this stalls concurrent requests as well, and repeated requests can render the service unresponsive. This affects the default configuration, since the vulnerable path is reached whenever cors() is used with an unset or empty allowHeaders. Applications that set a non-empty allowHeaders are not affected. This issue is fixed in version 4.12.34.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00609 49th percentileScored 2026-11-07

Fix Fixed hono (honojs): 4.12.34hono (npm): 4.12.34

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
honojs	hono	before 4.12.34	4.12.34	Patch available	CNA
—	hono (npm)	before 4.12.34	4.12.34	Patch available	GHSA-8j4g-w8fx-2239

hono Vendorhonojs Affected before 4.12.34 Fixed in 4.12.34 Patch available CNA
hono (npm) Vendor— Affected before 4.12.34 Fixed in 4.12.34 Patch available GHSA-8j4g-w8fx-2239

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:hono:hono::::::::	—	—	honojs

cpe:2.3:a:hono:hono:*:*:*:*:*:*:*:* Versions — — ·honojs

Remediation

Fix · CNA hono (honojs) Fixed in 4.12.34
Fix · GHSA-8j4g-w8fx-2239 hono (npm) Fixed in 4.12.34 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-69207
2026-10-03 Alias added: GHSA-8j4g-w8fx-2239

References

Other 4

TI-2024-21741 Hono vulnerable to Restricted Directory Traversal in serveStatic with deno CVSS 3.1MEDIUM 5.3
TI-2024-15441 @hono/node-server can't handle "double dots" in URL CVSS 3.1MEDIUM 5.3
TI-2024-32610 Hono vulnerable to bypass of CSRF Middleware by a request without Content-Type header. CVSS 3.1MEDIUM 5.9
TI-2024-29381 Hono CSRF middleware can be bypassed using crafted Content-Type header CVSS 3.1MEDIUM 5.0
TI-2026-39189 Hono: Lambda@Edge adapter keeps only the last value of a repeated request header, dropping the rest CVSS 3.1MEDIUM 4.8
TI-2026-23190 Hono: Arbitrary file access via serveStatic vulnerability CVSS 3.1CRITICAL 9.8

See all 59 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences