CVE-2026-48710

CRITICALNVD 6.59.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because this CVE is listed on the CISA Known Exploited Vulnerabilities catalog (added 2026-09-02), indicating real-world exploitation has been confirmed by US federal agencies. NVD baseline CVSS 6.5 retained for reference. Confidence: HIGH.

Triggered by: CISA KEV (actively exploited)
Sources: cisa_kev, epss, nvd
Trending — 4 sources updated this weekExploited in the wild
9.0EG
EchelonGraph verdictPatch nowTreat as an emergency — this is being exploited.
  • Actively exploited in the wild (CISA-KEV)
CISA-KEV: ExploitedEPSS PROB: 36%CVSS: 6.5Exploit: cisa kev · ssvc active · epss top5pct · public exploitExposed: 0

A fix is available — apply it.

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.

CVSS v3
6.5
EG Score
9.0(high)
EG Risk
96(Attend)
EG Risk 96/100SSVC: Attend

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation100% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
36%
EPSS %ILE
98%
KEV
⚠ Exploited

Published

May 26, 2026

Last Modified

September 4, 2026

Advisory Details (7)

Auto-updated Jun 15, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github.
generic🟡 PoC Available

Advisory X41-2026-002: Request Host Header not Validated in Starlette | X41 D-Sec - Penetration Tests and Source Code Audits

https://www.x41-dsec.de/lab/advisories/x41-2026-002-starlette
generic🟡 PoC Available

starlette - secwest.net - secure virtual engagement

https://www.secwest.net/starlette
generic

Disclosing the BADHOST Vulnerability in Starlette – OSTIF.org

https://ostif.org/disclosing-the-badhost-vulnerability-in-starlette
generic

advisory-database/vulns/starlette/PYSEC-2026-161.yaml at main · pypa/advisory-database · GitHub

https://github.com/pypa/advisory-database/tree/main/vulns/starlette/PYSEC-2026-161.yaml
github Patch Available

Missing Host header validation poisons request.url.path, bypassing path-based security checks · Advisory · Kludex/starlette · GitHub

https://github.com/Kludex/starlette/security/advisories/GHSA-86qp-5c8j-p5mr
github_commit Patch Available

commit 764dab0dcfb9 (Kludex/starlette)

Patch available: Kludex/starlette 1.0.1 (contains commit 764dab0dcfb9)

https://github.com/Kludex/starlette/commit/764dab0dcfb9033d75442d7a359645c9f94648c6
generic

BadHost - CVE-2026-48710 Starlette Host-Header Auth Bypass

https://badhost.org

Vendor Advisories for CVE-2026-48710(17)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(16)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatsatellite/iop-vulnerability-engine-rhel9:17881902242026-09-03redhat
redhatrhoai/odh-feature-server-rhel9:17870680652026-08-27redhat
redhatsatellite/iop-vulnerability-engine-rhel9:17845541232026-08-06redhat
redhatsatellite/iop-advisor-engine-rhel9:17848344022026-07-23redhat
redhatmta/mta-solution-server-rhel9:17841098832026-07-21redhat
redhatrhoai/odh-workbench-jupyter-tensorflow-cuda-py312-rhel9:17824717302026-07-09redhat
redhatsatellite/iop-vmaas-rhel9:17821396192026-07-01redhat
redhatsatellite/iop-host-inventory-rhel9:17804030262026-07-01redhat
redhatrhoai/odh-workbench-jupyter-trustyai-cpu-py312-rhel9:17821353002026-07-01redhat
redhatrhaiis/vllm-cuda-rhel9:17823528472026-06-25redhat
redhatrhaiis/vllm-rocm-rhel9:17823530932026-06-25redhat
redhatsatellite/iop-host-inventory-rhel9:17804142372026-06-16redhat
redhatansible-automation-platform-26/lightspeed-chatbot-rhel9:17801027322026-06-09redhat
redhatansible-automation-platform-27/lightspeed-chatbot-rhel9:17800991852026-06-04redhat
redhatsatellite/foreman-mcp-server-rhel9:17804920122026-06-03redhat
redhatsatellite/foreman-mcp-server-rhel9:17804920082026-06-03redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 5 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
starlette0.14.1-1 ... 1.3.1-1 (27 versions)——
Debian:12(1)
PackageVulnerable rangeFixed inDependents
starlette0.26.1-10.26.1-1+deb12u1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
starlette0.46.1-3, 0.46.1-3+deb13u10.46.1-3+deb13u2—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
starlette0.46.1-3, 0.50.0-1, 1.0.0-11.1.0-1—
PyPI(1)
PackageVulnerable rangeFixed inDependents
starlette0.1.0 ... 1.0.0rc1 (191 versions)1.0.1—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 57× in last 7d / 169× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 337 total refreshes for this CVE.

  1. 2026-09-19 02:49 UTCVendor advisory
  2. 2026-09-18 22:53 UTCEG score recompute
  3. 2026-09-18 22:53 UTCVendor advisory
  4. 2026-09-18 19:28 UTCEPSS rescore
  5. 2026-09-18 19:20 UTCCISA KEV update
  6. 2026-09-18 18:57 UTCVendor advisory
  7. 2026-09-18 15:01 UTCVendor advisory
  8. 2026-09-18 14:15 UTCCISA KEV update
  9. 2026-09-18 11:05 UTCVendor advisory
  10. 2026-09-18 07:08 UTCVendor advisory
  11. 2026-09-18 03:12 UTCVendor advisory
  12. 2026-09-17 23:16 UTCEG score recompute
  13. 2026-09-17 23:16 UTCVendor advisory
  14. 2026-09-17 19:20 UTCVendor advisory
  15. 2026-09-17 15:24 UTCVendor advisory
  16. 2026-09-17 11:28 UTCVendor advisory
  17. 2026-09-17 07:30 UTCVendor advisory
  18. 2026-09-17 03:34 UTCVendor advisory
  19. 2026-09-16 23:38 UTCVendor advisory
  20. 2026-09-16 19:42 UTCVendor advisory
  21. 2026-09-16 15:45 UTCEG score recompute
  22. 2026-09-16 15:45 UTCVendor advisory
  23. 2026-09-16 14:10 UTCCISA KEV update
  24. 2026-09-16 14:08 UTCEPSS rescore
  25. 2026-09-16 11:49 UTCVendor advisory
Show 75 more
  1. 2026-09-16 07:52 UTCEG score recompute
  2. 2026-09-16 07:52 UTCVendor advisory
  3. 2026-09-16 05:15 UTCEPSS rescore
  4. 2026-09-16 03:55 UTCVendor advisory
  5. 2026-09-15 23:57 UTCVendor advisory
  6. 2026-09-15 20:01 UTCVendor advisory
  7. 2026-09-15 16:04 UTCVendor advisory
  8. 2026-09-15 12:08 UTCVendor advisory
  9. 2026-09-15 08:12 UTCVendor advisory
  10. 2026-09-15 04:16 UTCEG score recompute
  11. 2026-09-15 04:16 UTCVendor advisory
  12. 2026-09-15 00:20 UTCVendor advisory
  13. 2026-09-14 20:24 UTCVendor advisory
  14. 2026-09-14 19:24 UTCCISA KEV update
  15. 2026-09-14 16:28 UTCVendor advisory
  16. 2026-09-14 12:32 UTCVendor advisory
  17. 2026-09-14 08:36 UTCVendor advisory
  18. 2026-09-14 04:39 UTCVendor advisory
  19. 2026-09-14 00:43 UTCVendor advisory
  20. 2026-09-13 20:47 UTCVendor advisory
  21. 2026-09-13 16:51 UTCEG score recompute
  22. 2026-09-13 16:51 UTCVendor advisory
  23. 2026-09-13 16:47 UTCEPSS rescore
  24. 2026-09-13 12:55 UTCVendor advisory
  25. 2026-09-13 08:59 UTCVendor advisory
  26. 2026-09-13 05:03 UTCVendor advisory
  27. 2026-09-13 01:07 UTCVendor advisory
  28. 2026-09-12 21:11 UTCVendor advisory
  29. 2026-09-12 17:15 UTCEG score recompute
  30. 2026-09-12 17:15 UTCVendor advisory
  31. 2026-09-12 13:19 UTCVendor advisory
  32. 2026-09-12 09:22 UTCVendor advisory
  33. 2026-09-12 05:25 UTCVendor advisory
  34. 2026-09-12 01:29 UTCVendor advisory
  35. 2026-09-11 21:33 UTCVendor advisory
  36. 2026-09-11 18:49 UTCCISA KEV update
  37. 2026-09-11 17:37 UTCEG score recompute
  38. 2026-09-11 17:37 UTCVendor advisory
  39. 2026-09-11 14:53 UTCEPSS rescore
  40. 2026-09-11 13:40 UTCVendor advisory
  41. 2026-09-11 09:43 UTCEG score recompute
  42. 2026-09-11 09:43 UTCVendor advisory
  43. 2026-09-11 05:47 UTCVendor advisory
  44. 2026-09-11 01:51 UTCVendor advisory
  45. 2026-09-10 21:54 UTCVendor advisory
  46. 2026-09-10 19:28 UTCCISA KEV update
  47. 2026-09-10 17:57 UTCVendor advisory
  48. 2026-09-10 14:00 UTCVendor advisory
  49. 2026-09-10 10:04 UTCEG score recompute
  50. 2026-09-10 10:04 UTCVendor advisory
  51. 2026-09-10 09:35 UTCEPSS rescore
  52. 2026-09-10 06:07 UTCVendor advisory
  53. 2026-09-10 02:10 UTCVendor advisory
  54. 2026-09-09 22:14 UTCVendor advisory
  55. 2026-09-09 19:08 UTCCISA KEV update
  56. 2026-09-09 18:16 UTCVendor advisory
  57. 2026-09-09 14:19 UTCVendor advisory
  58. 2026-09-09 10:23 UTCVendor advisory
  59. 2026-09-09 06:26 UTCVendor advisory
  60. 2026-09-09 02:30 UTCVendor advisory
  61. 2026-09-08 22:34 UTCEG score recompute
  62. 2026-09-08 22:34 UTCVendor advisory
  63. 2026-09-08 22:01 UTCEPSS rescore
  64. 2026-09-08 18:54 UTCCISA KEV update
  65. 2026-09-08 18:37 UTCVendor advisory
  66. 2026-09-08 14:40 UTCVendor advisory
  67. 2026-09-08 10:43 UTCVendor advisory
  68. 2026-09-08 06:46 UTCVendor advisory
  69. 2026-09-08 02:49 UTCVendor advisory
  70. 2026-09-07 22:53 UTCVendor advisory
  71. 2026-09-07 18:57 UTCEG score recompute
  72. 2026-09-07 18:57 UTCVendor advisory
  73. 2026-09-07 16:01 UTCEPSS rescore
  74. 2026-09-07 15:01 UTCVendor advisory
  75. 2026-09-07 11:05 UTCVendor advisory

Publicly available exploits

(2 references)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCeris-ths/supply-chain-guard
    First seen Apr 1, 2026

    Detect, assess, and respond to supply chain attacks across npm/yarn and Python (pip/poetry/uv). Claude Code skill + standalone scripts. Built during axios RAT (2026-03-31) and Starlette BadHost CVE-2026-48710 (2026-05-22).

    Open source ↗
  • Nucleihttp/cves/2026/CVE-2026-48710.yaml
    First seen Jan 1, 2026

    Starlette - Improper Validation of Unsafe Equivalence in Input

    Open source ↗

Frequently asked(6)

What is CVE-2026-48710?
CVE-2026-48710 is a critical vulnerability published on May 26, 2026. 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…
When was CVE-2026-48710 disclosed?
CVE-2026-48710 was first published in the National Vulnerability Database on May 26, 2026, with the most recent update on September 4, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-48710 actively exploited?
Yes. CISA added CVE-2026-48710 to the Known Exploited Vulnerabilities catalog on September 2, 2026, affecting Kludex Starlette. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.
What is the CVSS score of CVE-2026-48710?
CVE-2026-48710 has a CVSS v3 base score of 6.5 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
Which products are affected by CVE-2026-48710?
CVE-2026-48710 affects Kludex Starlette. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.
How do I remediate CVE-2026-48710?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48710, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-48710

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