{"cve":"CVE-2026-59897","nvd":{"published":"2026-07-08T17:17:27.637","modified":"2026-10-25T17:10:00.197","status":"Analyzed","description":"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_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":5.3},"cwes":["CWE-348"],"references":["https://github.com/honojs/hono/commit/aa921770d09bc35970362d5a2630a878f6d982fd","https://github.com/honojs/hono/releases/tag/v4.12.27","https://github.com/honojs/hono/security/advisories/GHSA-xgm2-5f3f-mvvc"],"products":["hono:hono"],"source":"nvd","synced_at":"2026-10-25T17:50:06.907763985+00:00"},"epss":{"cve":"CVE-2026-59897","score":0.0018,"percentile":0.07471,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-xgm2-5f3f-mvvc","url":"https://osv.dev/vulnerability/GHSA-xgm2-5f3f-mvvc","summary":"Hono: API Gateway v1 adapter can drop a distinct repeated request header value during de-duplication","modified":"2026-09-10T03:50:53.167967172Z","packages":[{"ecosystem":"npm","name":"hono","purl":"pkg:npm/hono","ranges":[">=4.3.3 <4.12.27"],"fixed":["4.12.27"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}