Skip to content
vulnerability

CVE-2026-48710

6.5
Medium
KEV · Exploited in wildEPSS 70%Patch available

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.

exploited
Yes, in CISA KEV since 2 Sept 2026fix by 16 Sept 2026 (CISA deadline for US federal agencies)unvetted proof-of-concept code on github
fix
Patch available see the advisory in the references
likelihood
EPSS 70.3%
Published 26 May 2026Analysed here 2 Nov 2026CVSS scored by the publisher (CNA)

do firstApply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

triage
surface unknownruntimeWAF can block: partlyAV · networkCWE-444· Common WeaknessCWE-1289· Common Weakness

Can a WAF block it? Partly. The attack involves sending an HTTP request with a malformed Host header that is not properly validated, which can cause the application to reconstruct the URL incorrectly and bypass security checks. A WAF can detect and block requests with malformed Host headers that do not conform to expected syntax. A WAF rule can match malformed Host header in HTTP request. No tracked WAF vendor has published a rule for this CVE yet, so you would write it yourself.

What a custom rule would match: malformed Host header in HTTP request

Also consider: patch · custom WAF rule

Based on an AI reading of the CVE description, and no vendor rule found yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.

cvss vector
attack vectornetworkattack complexitylowprivileges requirednoneuser interactionnonescopeunchangedconfidentialitylowintegritylowavailabilitynone
CVSS 3.1 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
common questions

Is CVE-2026-48710 being exploited?

Yes. CVE-2026-48710 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.

How severe is CVE-2026-48710?

CVE-2026-48710 is rated Medium with a CVSS score of 6.5. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2026-48710?

Yes. A fix has been recorded for CVE-2026-48710. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2026-48710 affect?

CVE-2026-48710 affects encode:starlette, redhat:ai_inference_server, redhat:ansible_automation_platform, redhat:migration_toolkit_for_applications, and 4 further products or versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
affected
encode:starletteredhat:ai_inference_serverredhat:ansible_automation_platformredhat:migration_toolkit_for_applicationsredhat:openshift_airedhat:openshift_lightspeedredhat:satelliteredhat:enterprise_linux_ai
affected versions
Kludex starlette
  • affected< 1.0.1

As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

public exploits

Unvetted proof-of-concept code on GitHub: 5 GitHub proofs of concept · 1 Nuclei template

Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.

cisa ssvc

exploitation
active
automatable
yes
technical impact
partial

Assessed by CISA 3 Sept 2026 (SSVC 2.0.3).

timeline

  1. 1 Apr 2026First proof-of-concept repository on GitHub (unvetted)
  2. 26 May 2026Published · 56 days later
  3. 2 Sept 2026Added to CISA KEV (exploited in the wild) · 98 days (about 3 months) later
  4. 3 Sept 2026CISA SSVC assessment: exploitation active · 1 day later
  5. 16 Sept 2026CISA remediation due date (US federal agencies) · 13 days later
  6. 1 Oct 2026CVE record last updated · 16 days later
  7. 2 Nov 2026Analysed by vulneraibility.com · 32 days later

also known as

GHSA-86qp-5c8j-p5mrPYSEC-2026-161
how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
NVDCVE.orgCVE DetailsSource
28 references in the CVE record: 17 advisories, 11 links
Show 20 more

sources

  • CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
  • NVD: CVSS and CPE data
  • CISA KEV catalog: exploitation, date added, due date
  • CISA Vulnrichment (ADP): SSVC decision points
  • FIRST EPSS: exploit probability and percentile
  • Nuclei templates: detection templates
  • PoC-in-GitHub: GitHub repositories that claim a proof of concept
  • OSV: advisory aliases and downstream package versions
  • Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
get alerted

Track only the vulnerabilities that affect your infrastructure.

start for free

© 2026 vulneraibility.com, all rights reserved