CVE-2026-48710
Description
Starlette is a lightweight ASGI framework/toolkit. Prior to version 1.0.1, the HTTP Host request header was not validated before being used to reconstruct request.url. Because the routing algorithm relies on the raw HTTP path while request.url is rebuilt from the Host header, a malformed header could make request.url.path differ from the path that was actually requested. Middleware and endpoints that apply security restrictions based on request.url (rather than the raw scope path) could therefore be bypassed. Users should upgrade to a version greater than or equal to version 1.0.1, which validates the Host header against the grammar of RFC 9112 §3.2 / RFC 3986 §3.2.2 when constructing request.url and falls back to scope["server"] for malformed values.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
starlettePyPI | < 1.0.1 | 1.0.1 |
Affected products
12- osv-coords9 versionspkg:apk/chainguard/nemopkg:apk/chainguard/tritonserver-backend-vllm-cuda-12.9pkg:apk/chainguard/wazuh-manager-frameworkpkg:apk/chainguard/wazuh-manager-framework-fipspkg:rpm/opensuse/python-google-adk&distro=openSUSE%20Tumbleweedpkg:rpm/opensuse/python-starlette&distro=openSUSE%20Leap%2016.0pkg:rpm/opensuse/python-starlette&distro=openSUSE%20Tumbleweedpkg:rpm/suse/python-starlette&distro=SUSE%20Linux%20Enterprise%20Server%2016.0pkg:rpm/suse/python-starlette&distro=SUSE%20Linux%20Enterprise%20Server%20for%20SAP%20applications%2016.0
< 2.7.3-r6+ 8 more
- (no CPE)range: < 2.7.3-r6
- (no CPE)range: < 25.9.0_git20260617-r0
- (no CPE)range: < 4.14.5-r2
- (no CPE)range: < 4.14.5-r3
- (no CPE)range: < 2.2.0-1.1
- (no CPE)range: < 0.41.3-160000.3.1
- (no CPE)range: < 1.2.0-1.1
- (no CPE)range: < 0.41.3-160000.3.1
- (no CPE)range: < 0.41.3-160000.3.1
Patches
Vulnerability mechanics
References
12- github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6nvdPatchWEB
- www.secwest.net/starlettenvdExploitMitigationThird Party AdvisoryWEB
- www.x41-dsec.de/lab/advisories/x41-2026-002-starlettenvdExploitMitigationThird Party AdvisoryWEB
- badhost.orgnvdMitigationThird Party AdvisoryWEB
- github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mrnvdVendor AdvisoryWEB
- github.com/advisories/GHSA-86qp-5c8j-p5mrghsaADVISORY
- github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yamlnvdThird Party AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-48710ghsaADVISORY
- ostif.org/disclosing-the-badhost-vulnerability-in-starlettenvdMitigationThird Party AdvisoryWEB
- access.redhat.com/security/cve/CVE-2026-48710nvd
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48710.jsonnvd
- www.cve.org/CVERecordnvd
News mentions
4- LiteLLM vulnerability under active attack, CISA warns (CVE-2026-42271)Help Net Security · Jun 9, 2026
- Hackers Exploiting LiteLLM RCE Vulnerability in the Wild to Run Arbitrary CommandsCyber Security News · Jun 9, 2026
- LiteLLM Flaw CVE-2026-42271 Exploited in the Wild, Chains to Unauthenticated RCEThe Hacker News · Jun 9, 2026
- Attackers Can Exploit BadHost to Access Sensitive AI Agent Server EndpointsCyber Security News · May 27, 2026