CVE-2026-84365Network attack vectorHinoki check available

Build artifact overwrite via incomplete path normalization

Published Sep 1, 2026 · Updated Sep 1, 2026

Path traversal in Hono before 4.13.5 allows attackers to write files outside the output directory during static site generation. The toSSG() path builder and containment check share a normalization routine that fails to collapse consecutive parent-directory segments, so an accepted path resolves beyond the configured root. Exploitation requires a build to use untrusted ssgParams values; request-time routing and builds with developer-controlled parameters are unaffected.

CVSS severity6.5
Medium
EPSS probability0.33%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Path traversal in Hono before 4.13.5 allows attackers to write files outside the output directory during static site generation. The toSSG() path builder and containment check share a normalization routine that fails to collapse consecutive parent-directory segments, so an accepted path resolves beyond the configured root. Exploitation requires a build to use untrusted ssgParams values; request-time routing and builds with developer-controlled parameters are unaffected.

The record

CVE
CVE-2026-84365
Published
Sep 1, 2026
Updated
Sep 1, 2026
Vendor
Hono
Product
Hono
Classifications
CWE-22, T1565.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 1, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 1, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 4.13.5

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Hono · Honoversion=< 4.13.5

Published CVSS scores

6.5GitHub CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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