GHSA-5r4p-p66f-jhc7: hono (CVE-2026-109955)

Package	Ecosystem	Affected	Fixed in
hono	npm	>=4.12.4, <4.13.11	4.13.11

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Hono (npm package hono) versions >=4.12.4 and <4.13.11 are vulnerable. Because serveStatic decodes the request path a second time, a crafted request with a malformed percent-encoded sequence can bypass middleware mounted on a static prefix, such as an authentication check, while the file is still served from within the configured root. The source says an unauthenticated attacker can exploit this, and that only applications that mount middleware on part of a directory served by serveStatic are affected. Upgrade to hono 4.13.11, which is the fixed version.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
6.9	Medium	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0032, the 24th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 13:33 UTC First seen by agentprime
31 Oct 2026, 13:33 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.