Read the docs
TI-2026-39187 Aliases CVE-2026-54287GHSA-j6c9-x7qj-28xf

Improper output encoding in honojs hono

Priority LOW 30CWE-116Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub.

Summary

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.12.25, on AWS Lambda, the ALB single-header response and the VPC Lattice v2 response join multiple Set-Cookie headers into one comma-separated value. Because commas also appear inside cookie attributes (for example Expires dates), clients cannot split the value back into individual cookies and silently drop or misparse them. This vulnerability is fixed in 4.12.25.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0031 24th percentileScored 2026-11-07
Fix Fixed hono (honojs): 4.12.25hono (npm): 4.12.25

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

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

Affected products

VendorProductAffected versionsFixed inStatusSource
honojshonobefore 4.12.254.12.25Patch availableCNA
—hono (npm)before 4.12.254.12.25Patch availableGHSA-j6c9-x7qj-28xf
  • hono Vendorhonojs Affected before 4.12.25 Fixed in 4.12.25 Patch available CNA
  • hono (npm) Vendor— Affected before 4.12.25 Fixed in 4.12.25 Patch available GHSA-j6c9-x7qj-28xf

CPE names Threatist (inferred) · 1

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

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

Remediation

  • Fix · CNA hono (honojs) Fixed in 4.12.25
  • Fix · GHSA-j6c9-x7qj-28xf hono (npm) Fixed in 4.12.25 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-54287
  2. 2026-10-03 Alias added: GHSA-j6c9-x7qj-28xf

References

Advisory 1

Other 2

  • 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