CVE-2026-71849: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in honojs hono
A vulnerability in the honojs hono web framework versions 4.7.0 through 4.12.33 allows exposure of sensitive information due to improper handling of response headers in the proxy() function. The function fails to remove headers named by the origin's Connection header as required by RFC 9110, potentially disclosing internal or connection-scoped metadata to clients. This issue is fixed in version 4.12.34. The vulnerability has a low severity score of 3.7 and does not affect cloud services.
AI Analysis
Technical Summary
The honojs hono framework's proxy() function in versions 4.7.0 to 4.12.33 does not remove response headers specified by the origin's Connection header, violating RFC 9110 Section 7.6.1 requirements. While it removes well-known hop-by-hop headers, it neglects additional non-standard headers declared as hop-by-hop by the origin. This can cause clients to receive headers intended only for immediate peers, potentially exposing sensitive connection-scoped or internal metadata. The issue is resolved in version 4.12.34.
Potential Impact
Clients may receive response headers that the origin intended only for its immediate peer, which can disclose sensitive connection-scoped or internal metadata. The impact is limited to information disclosure with no integrity or availability effects. The CVSS score is 3.7 (low severity).
Mitigation Recommendations
Upgrade to hono version 4.12.34 or later, where the proxy() function correctly removes all headers named by the origin's Connection header as required by RFC 9110. No other mitigation is indicated.
CVE-2026-71849: CWE-200: Exposure of Sensitive Information to an Unauthorized Actor in honojs hono
Description
A vulnerability in the honojs hono web framework versions 4.7.0 through 4.12.33 allows exposure of sensitive information due to improper handling of response headers in the proxy() function. The function fails to remove headers named by the origin's Connection header as required by RFC 9110, potentially disclosing internal or connection-scoped metadata to clients. This issue is fixed in version 4.12.34. The vulnerability has a low severity score of 3.7 and does not affect cloud services.
CVSS v3.1
Score 3.7low
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The honojs hono framework's proxy() function in versions 4.7.0 to 4.12.33 does not remove response headers specified by the origin's Connection header, violating RFC 9110 Section 7.6.1 requirements. While it removes well-known hop-by-hop headers, it neglects additional non-standard headers declared as hop-by-hop by the origin. This can cause clients to receive headers intended only for immediate peers, potentially exposing sensitive connection-scoped or internal metadata. The issue is resolved in version 4.12.34.
Potential Impact
Clients may receive response headers that the origin intended only for its immediate peer, which can disclose sensitive connection-scoped or internal metadata. The impact is limited to information disclosure with no integrity or availability effects. The CVSS score is 3.7 (low severity).
Mitigation Recommendations
Upgrade to hono version 4.12.34 or later, where the proxy() function correctly removes all headers named by the origin's Connection header as required by RFC 9110. No other mitigation is indicated.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-08-07T18:26:53.523Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a762a7bbf8831d539f90bfe
Added to database: 08/07/2026, 18:56:59 UTC
Last enriched: 08/07/2026, 19:16:46 UTC
Last updated: 08/07/2026, 19:16:46 UTC
Views: 4
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