{"id":"CVE-2026-27700","summary":"Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo","details":"Hono is a Web application framework that provides support for any JavaScript runtime. In versions 4.12.0 and 4.12.1, when using the AWS Lambda adapter (`hono/aws-lambda`) behind an Application Load Balancer (ALB), the `getConnInfo()` function incorrectly selected the first value from the `X-Forwarded-For` header. Because AWS ALB appends the real client IP address to the end of the `X-Forwarded-For` header, the first value can be attacker-controlled. This could allow IP-based access control mechanisms (such as the `ipRestriction` middleware) to be bypassed. Version 4.12.2 patches the issue.","aliases":["GHSA-xh87-mx6m-69f3"],"modified":"2026-08-12T03:51:46.124816231Z","published":"2026-02-25T15:01:44.681Z","related":["CGA-g73x-7r4q-76qh"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27700.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-290","CWE-345"]},"references":[{"type":"WEB","url":"https://github.com/honojs/hono/releases/tag/v4.12.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27700.json"},{"type":"ADVISORY","url":"https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27700"},{"type":"FIX","url":"https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/honojs/hono","events":[{"introduced":"d2ed2e9c966d82e2369bd74bdae4acd4e8f57807"},{"fixed":"df97e5f49771a2a219770515859b9cc1d80abab0"},{"fixed":"41adbf56e252c04611f8972364ac0887ae07a4c7"}],"database_specific":{"cpe":"cpe:2.3:a:hono:hono:*:*:*:*:*:node.js:*:*","extracted_events":[{"introduced":"4.12.0"},{"fixed":"4.12.2"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["v4.12.1","v4.12.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27700.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N"}]}