{"id":"CVE-2026-48061","summary":"Litestar: AllowedHostsMiddleware bypasses host validation via client-controlled X-Forwarded-Host header","details":"Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. In versions prior to 2.22.0, an attacker can bypass the allowed hosts validation by omitting the Host header and supplying an X-Forwarded-Host header set to a whitelisted domain. The AllowedHostsMiddleware trusts the X-Forwarded-Host header as a fallback when the Host header is absent. Since X-Forwarded-Host is a client-controllable header, this enables host header injection attacks such as password reset poisoning, cache poisoning, and server-side request routing manipulation. Any application using AllowedHostsConfig is affected when deployed without a reverse proxy that strips X-Forwarded-Host, or when accepting HTTP/1.0 connections. This issue has been fixed in version 2.22.0.","aliases":["GHSA-3qmc-cj7q-62hv","PYSEC-2026-2603"],"modified":"2026-08-07T11:51:16.515577302Z","published":"2026-08-03T20:47:34.673Z","database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-644"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48061.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48061.json"},{"type":"ADVISORY","url":"https://github.com/litestar-org/litestar/security/advisories/GHSA-3qmc-cj7q-62hv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48061"},{"type":"FIX","url":"https://github.com/litestar-org/litestar/commit/6930a20ceb543912cd651b42deae5b9f3637a262"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/litestar-org/litestar","events":[{"introduced":"0"},{"fixed":"6930a20ceb543912cd651b42deae5b9f3637a262"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"2.22.0"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v2.21.1","v2.21.0","v2.20.0","v2.19.0","v2.18.0","v2.17.0","v2.16.0","v2.15.2","v2.15.1","v2.15.0","v2.14.0","v2.13.0","v2.12.1","v2.12.0","v2.11.0","v2.10.0","v2.9.0","v2.7.1","v2.6.3","v2.8.0","v2.7.0","v2.6.2","v2.6.1","v2.6.0","v2.5.5","v2.5.4","v2.5.3","v2.5.2","v2.5.1","v2.5.0","v2.4.5","v2.4.4","v2.4.3","v2.4.2","v2.4.1","v2.4.0","v2.3.2","v2.3.1","v2.3.0","v2.2.1","v2.2.0","v2.1.1","v2.1.0","v2.0.0","v2.0.0rc1","v2.0.0beta4","v2.0.0beta3","v2.0.0beta2","v2.0.0beta1","v2.0.0alpha7","v2.0.0alpha6","v2.0.0alpha5","v2.0.0alpha4","v2.0.0alpha3","v2.0.0alpha2","v2.0.0alpha1","v1.51.0","v1.50.2","v1.50.1","v1.50.0","v1.49.0","v1.48.1","v1.48.0","v1.47.0","v1.46.0","v1.45.1","v1.45.0","v1.44.0","v1.43.1","v1.43.0","v1.42.0","v1.41.0","v1.40.1","v1.40.0","v1.39.0","v1.38.0","v1.37.0","v1.36.0","v1.35.1","v1.35.0","v1.34.0","v1.33.0","v1.32.0","v1.31.0","v1.30.0","v1.29.0","v1.28.1","v1.28.0","v1.27.0","v1.26.1","v1.26.0","v1.25.0","v1.24.0","v1.23.1","v1.23.0","v1.22.0","v1.21.2","v1.21.1","v1.21.0","v1.20.0","v1.19.0","v1.18.1","v1.18.0","v1.17.2","v1.17.1","v1.17.0","v1.16.2","v1.16.1","v1.16.0","v1.15.0","v1.14.2","v1.14.1","v1.14.0","v1.13.1","v1.13.0","v1.12.0","v1.11.1","v1.11.0","v1.10.1","v1.10.0","v1.9.1","v1.9.0","v1.8.1","v1.8.0","v1.7.3","v1.7.1","v1.7.0","v1.6.3","v1.6.2","v1.6.1","v1.6.0","v1.5.4","v1.5.3","v1.5.2","v1.5.1","v1.5.0","v1.4.2","v1.4.1","v1.4.0","v1.3.9","v1.3.8","v1.3.7","v1.3.6","v1.3.5","v1.3.4","v1.3.3","v1.3.2","v1.3.1","v1.3.0","v1.2.5","v1.2.4","v1.2.3","v1.2.2","v1.2.1","v1.2.0","v1.1.1","v1.0.4","v1.1.0","v1.0.5","v1.0.3","v1.0.2","v1.0.1","v1.0.0","0.7.2","v0.7.1","v0.7.0","v0.6.0","v0.5.0","v0.4.3","v0.4.2","v0.4.1","v0.4.0","v0.3.0","v0.2.1","v0.2.0","v0.1.6","v0.1.5","v0.1.4","v0.1.3","v0.1.2","v0.1.1","v0.1.0","v0.1.0b1","v0.0.1a"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48061.json"}}],"schema_version":"1.8.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N"}]}