{"id":"CVE-2026-27700","state":"PUBLISHED","title":"Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo","description":"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.","publishedAt":"2026-02-25T15:01:44.681Z","updatedAt":"2026-02-27T17:01:28.403Z","severity":{"score":8.2,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["honojs hono"],"affected":[{"vendor":"honojs","product":"hono","versions":[{"version":">= 4.12.0, < 4.12.2","status":"affected"}]}],"references":["https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3","https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7","https://github.com/honojs/hono/releases/tag/v4.12.2"],"weaknesses":["CWE-345","CWE-290"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/27xxx/CVE-2026-27700.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27700","state":"PUBLISHED","datePublished":"2026-02-25T15:01:44.681Z","dateUpdated":"2026-02-27T17:01:28.403Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-23T17:56:51.202Z"},"containers":{"cna":{"title":"Hono is Vulnerable to Authentication Bypass by IP Spoofing in AWS Lambda ALB conninfo","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"honojs","product":"hono","versions":[{"version":">= 4.12.0, < 4.12.2","status":"affected"}]}],"references":[{"url":"https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3","name":"https://github.com/honojs/hono/security/advisories/GHSA-xh87-mx6m-69f3","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7","name":"https://github.com/honojs/hono/commit/41adbf56e252c04611f8972364ac0887ae07a4c7","tags":["x_refsource_MISC"]},{"url":"https://github.com/honojs/hono/releases/tag/v4.12.2","name":"https://github.com/honojs/hono/releases/tag/v4.12.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":8.2,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"CWE-345: Insufficient Verification of Data Authenticity","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-290","lang":"en","description":"CWE-290: Authentication Bypass by Spoofing","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-02-25T15:01:44.681Z"},"source":{"advisory":"GHSA-xh87-mx6m-69f3","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-02-27T17:01:17.956003Z","id":"CVE-2026-27700","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-02-27T17:01:28.403Z"}}]}}}