CVE-2026-59897
MEDIUMDescription
Hono is a Web application framework that provides support for any JavaScript runtime. From 4.3.3 before 4.12.27, the AWS API Gateway v1 adapter can drop a distinct repeated request header value because it de-duplicates values using a substring comparison instead of an exact match, so middleware or application logic that depends on the complete X-Forwarded-For chain, rate limiting, audit logging, or proxy-chain validation can receive incomplete data. This issue is fixed in version 4.12.27.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Exploit Intelligence
Low risk: more likely to be exploited than 3% of all known CVEs.
References
Related Vulnerabilities
Other CWE-348 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-59951 | Critical | 9.1 | 4.7% | - | - |
| CVE-2022-31813 | Critical | 9.8 | 3.3% | - | Fix |
| CVE-2024-45410 | Critical | 9.8 | 1.5% | - | Fix |
| CVE-2021-21373 | High | 7.5 | 1.2% | - | Fix |
| CVE-2021-21374 | High | 8.1 | 1.0% | - | Fix |
| CVE-2022-2255 | High | 7.5 | 0.7% | - | Fix |
Common questions
How do I fix CVE-2026-59897?
Upgrade hono to 4.12.27 or later.
Is CVE-2026-59897 being actively exploited?
Not that we know of. CVE-2026-59897 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.13% is the estimated probability that it will be exploited in the next 30 days. That is higher than 3% of all scored CVEs.
How severe is CVE-2026-59897?
CVE-2026-59897 has a CVSS v3 base score of 4.8, rated medium. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-59897 affect?
Published advisories record a fix for hono (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2026-59897
Markdown
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TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-10.