{"id":"CVE-2026-72817","state":"PUBLISHED","title":"go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For","description":"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.","publishedAt":"2026-08-14T11:35:28.824Z","updatedAt":"2026-10-08T15:24:32.174Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"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","source":"VulnCheck"},"assigner":"VulnCheck","products":["go-chi chi"],"affected":[{"vendor":"go-chi","product":"chi","packageURL":"pkg:golang/github.com/go-chi/chi","defaultStatus":"unaffected","versions":[{"version":"0.9.0","status":"affected","lessThan":"5.3.0","versionType":"semver"},{"version":"5.3.0","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf","https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for"],"weaknesses":["CWE-345"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72817.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72817","state":"PUBLISHED","datePublished":"2026-08-14T11:35:28.824Z","dateUpdated":"2026-10-08T15:24:32.174Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-08-10T15:12:16.754Z"},"containers":{"cna":{"title":"go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"go-chi","product":"chi","packageURL":"pkg:golang/github.com/go-chi/chi","defaultStatus":"unaffected","versions":[{"version":"0.9.0","status":"affected","lessThan":"5.3.0","versionType":"semver"},{"version":"5.3.0","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/go-chi/chi/security/advisories/GHSA-9g5q-2w5x-hmxf","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-9g5q-2w5x-hmxf)"},{"url":"https://www.vulncheck.com/advisories/go-chi-chi-before-ip-spoofing-via-x-forwarded-for","name":"VulnCheck Advisory: go-chi chi 0.9.0 before 5.3.0 IP Spoofing via X-Forwarded-For","tags":["third-party-advisory"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":6.9,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS"},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-345","lang":"en","description":"Insufficient Verification of Data Authenticity","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-08T15:24:32.174Z"},"datePublic":"2026-05-22T00:00:00.000Z","credits":[{"lang":"en","value":"convto","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-17T15:44:55.846871Z","id":"CVE-2026-72817","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":"2026-08-17T16:09:15.028Z"}}]}}}