{"id":"UBUNTU-CVE-2026-72817","details":"go-chi/chi versions 0.9.0 before 5.3.0 contains an IP spoofing vulnerability in the RealIP middleware, which resolves the request source IP (Request.RemoteAddr) using the first IP in the X-Forwarded-For header without validating trusted proxies. A malicious client can prepend a forged IP as the first value of the X-Forwarded-For header to spoof the request source IP, potentially bypassing access controls or falsifying request logs.","modified":"2026-08-19T11:11:14Z","published":"2026-08-14T12:16:00Z","upstream":["CVE-2026-72817"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-72817"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-72817"},{"type":"REPORT","url":"https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for"}],"affected":[{"package":{"name":"golang-github-go-chi-chi","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/golang-github-go-chi-chi?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.1-2","5.0.7-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-go-chi-chi-dev","binary_version":"5.0.7-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-72817.json"}},{"package":{"name":"golang-github-go-chi-chi","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/golang-github-go-chi-chi?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.0.7-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-go-chi-chi-dev","binary_version":"5.0.7-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-72817.json"}},{"package":{"name":"golang-github-go-chi-chi","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/golang-github-go-chi-chi?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.2.0-1","5.2.3-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-go-chi-chi-dev","binary_version":"5.2.3-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-72817.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:L/I:L/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}