CVE-2026-59897

MEDIUMNVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under NVD CVSS v3. EPSS exploit probability: 0.1%, top 97% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 4 sources updated this week
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
5.3
EG Score
5.3(medium)
EPSS
2.5%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 10, 2026

Advisory Details (3)

Auto-updated Jul 8, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

API Gateway v1 adapter can drop a distinct repeated request header value during de-duplication · Advisory · honojs/hono · GitHub

https://github.com/honojs/hono/security/advisories/GHSA-xgm2-5f3f-mvvc
github_release Patch Available

v4.12.27

Patch available: honojs/hono v4.12.27

https://github.com/honojs/hono/releases/tag/v4.12.27
github_commit Patch Available

commit aa921770d09b (honojs/hono)

Patch available: honojs/hono v4.12.27 (contains commit aa921770d09b)

https://github.com/honojs/hono/commit/aa921770d09bc35970362d5a2630a878f6d982fd

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 10× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-11 19:08 UTCEG score recompute▲ 0.50
  2. 2026-07-11 08:27 UTCEPSS rescore
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-10 20:19 UTCNVD updateCVSS v3 → 5.3
  5. 2026-07-10 18:16 UTCEG score recompute
  6. 2026-07-09 19:10 UTCEPSS rescore
  7. 2026-07-09 19:10 UTCEPSS rescore
  8. 2026-07-09 17:21 UTCEG score recompute
  9. 2026-07-08 16:25 UTCEG score recompute
  10. 2026-07-08 16:24 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-59897?
CVE-2026-59897 is a medium vulnerability published on July 8, 2026. 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…
When was CVE-2026-59897 disclosed?
CVE-2026-59897 was first published in the National Vulnerability Database on July 8, 2026, with the most recent update on July 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-59897 actively exploited?
CVE-2026-59897 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 2.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-59897?
CVE-2026-59897 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-59897?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-59897, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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