{"id":"CVE-2026-59897","sourceIdentifier":"security-advisories@github.com","published":"2026-07-08T17:17:27.637","lastModified":"2026-07-10T19:50:16.717","vulnStatus":"Analyzed","cveTags":[],"descriptions":[{"lang":"en","value":"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."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"honojs","product":"hono","versions":[{"version":">= 4.3.3, < 4.12.27","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","baseScore":4.8,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":2.2,"impactScore":2.5},{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","baseScore":5.3,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-07-09T13:51:23.283182Z","id":"CVE-2026-59897","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-348"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*","versionStartIncluding":"4.3.3","versionEndExcluding":"4.12.27","matchCriteriaId":"3B34D77B-60D8-4235-8A45-055C0B65B608"}]}]}],"references":[{"url":"https://github.com/honojs/hono/commit/aa921770d09bc35970362d5a2630a878f6d982fd","source":"security-advisories@github.com","tags":["Patch"]},{"url":"https://github.com/honojs/hono/releases/tag/v4.12.27","source":"security-advisories@github.com","tags":["Release Notes"]},{"url":"https://github.com/honojs/hono/security/advisories/GHSA-xgm2-5f3f-mvvc","source":"security-advisories@github.com","tags":["Vendor Advisory"]}]}