CVE-2026-39408: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in honojs hono
CVE-2026-39408 is a path traversal vulnerability in the hono JavaScript web application framework prior to version 4. 12. 12. The issue occurs in the toSSG() function used for static site generation, where specially crafted dynamic route parameters (ssgParams) can cause files to be written outside the intended output directory. This allows an attacker to escape the configured directory restriction. The vulnerability has a medium severity with a CVSS score of 5. 9 and is fixed in version 4. 12. 12.
AI Analysis
Technical Summary
Hono versions before 4.12.12 contain a path traversal vulnerability (CWE-22) in the toSSG() function. When generating static sites, dynamic route parameters can be manipulated to cause file writes outside the configured output directory. This improper limitation of pathname allows an attacker to potentially write files to arbitrary locations on the filesystem. The vulnerability is addressed by updating to version 4.12.12, which corrects the pathname restriction.
Potential Impact
An attacker exploiting this vulnerability can cause files to be written outside the intended output directory during static site generation. This could lead to unauthorized file creation or overwriting on the host filesystem, potentially impacting system integrity or security depending on the environment where hono is used.
Mitigation Recommendations
Upgrade hono to version 4.12.12 or later, where this path traversal vulnerability is fixed. Since the vendor advisory indicates the issue is resolved in this version, applying this official fix is the recommended remediation. Patch status is confirmed by the vendor advisory stating the fix is in 4.12.12.
CVE-2026-39408: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') in honojs hono
Description
CVE-2026-39408 is a path traversal vulnerability in the hono JavaScript web application framework prior to version 4. 12. 12. The issue occurs in the toSSG() function used for static site generation, where specially crafted dynamic route parameters (ssgParams) can cause files to be written outside the intended output directory. This allows an attacker to escape the configured directory restriction. The vulnerability has a medium severity with a CVSS score of 5. 9 and is fixed in version 4. 12. 12.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Hono versions before 4.12.12 contain a path traversal vulnerability (CWE-22) in the toSSG() function. When generating static sites, dynamic route parameters can be manipulated to cause file writes outside the configured output directory. This improper limitation of pathname allows an attacker to potentially write files to arbitrary locations on the filesystem. The vulnerability is addressed by updating to version 4.12.12, which corrects the pathname restriction.
Potential Impact
An attacker exploiting this vulnerability can cause files to be written outside the intended output directory during static site generation. This could lead to unauthorized file creation or overwriting on the host filesystem, potentially impacting system integrity or security depending on the environment where hono is used.
Mitigation Recommendations
Upgrade hono to version 4.12.12 or later, where this path traversal vulnerability is fixed. Since the vendor advisory indicates the issue is resolved in this version, applying this official fix is the recommended remediation. Patch status is confirmed by the vendor advisory stating the fix is in 4.12.12.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-04-07T00:23:30.594Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d737061cc7ad14da419553
Added to database: 4/9/2026, 5:20:06 AM
Last enriched: 4/9/2026, 5:27:50 AM
Last updated: 4/9/2026, 7:44:27 AM
Views: 5
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