CVE Intelligence
CISA KEV Medium Injection exploit reference

CVE-2026-48710 — Kludex Starlette HTTP Request/Response Smuggling Vulnerability

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.

Published May 26, 2026 · Updated Oct 13, 2026 · Sources: CISA Known Exploited Vulnerabilities, NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: GitHub_M

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

CISA KEV · Sep 2, 2026 Detection templates (Nuclei) · 1Proofs of concept on GitHub · 5
How the score was calculated
  • Confirmed exploitation (CISA KEV)+35
  • Public exploit/PoC (nuclei, github)+10
  • EPSS 7.1% (30-day exploitation probability)+14
  • Technical severity (medium)+3
  • Automatable exploitation (SSVC)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Confirmed
CISA KEV, listed Sep 2, 2026
EPSS FIRST
7.06%
ahead of 94% of scored CVEs · Oct 14, 2026
Affects
Encode
Starlette and 7 more
CVSS base
6.5
Medium · 5 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
Active
none · proof-of-concept · active
Automatable
Yes
can an attacker script the kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

  • Documented mitigation — badhost.org (NIST National Vulnerability Database)
  • Documented patch — github.com (NIST National Vulnerability Database)
  • Documented mitigation — ostif.org (NIST National Vulnerability Database)
  • Documented mitigation — www.secwest.net (NIST National Vulnerability Database)
  • Documented mitigation — www.x41-dsec.de (NIST National Vulnerability Database)
  • Pip Starlette: fixed in version 1.0.1 — github.com (GitHub Security Advisories)

CISA required action CISA

Apply 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.

US federal deadline: Sep 16, 2026 — passed 29 day(s) ago

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Encode Starlette, Kludex Starlette, Red Hat Ai Inference Server…).
  2. Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
  3. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  4. Apply the fixed version or the patch documented under Remediation.
  5. EPSS ahead of 94% of scored CVEs: prioritize it in the patch queue.
  6. Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Encode Starlette ≥ 0.8.3 and < 1.0.1 Vulnerable NIST National Vulnerability Database
Kludex Starlette version < 1.0.1 Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Ai Inference Server ≥ 3.3.0 and ≤ 3.3.5 Vulnerable NIST National Vulnerability Database
Red Hat Ansible Automation Platform version 2.6version 2.7 Vulnerable NIST National Vulnerability Database
Red Hat Enterprise Linux Ai version 3.0 Vulnerable NIST National Vulnerability Database
Red Hat Migration Toolkit For Applications < 8.2.0 Vulnerable NIST National Vulnerability Database
Red Hat Openshift Ai ≥ 3.3 and < 3.3.5≥ 3.4 and < 3.4.2 Vulnerable NIST National Vulnerability Database
Red Hat Openshift Lightspeed versions not specified by the source Vulnerable NIST National Vulnerability Database
Red Hat Satellite version 6.17version 6.18version 6.19 Vulnerable NIST National Vulnerability Database
Pip Starlette ≤ 1.0.0 Vulnerable GitHub Security Advisories

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.5 CVSS 3.1 Medium 3.9 2.5 security-advisories@github.com via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium 3.9 2.5 nvd@nist.gov via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium 3.9 2.5 0b0ca135-0b70-47e7-9f44-1890c2a1c46c via NIST National Vulnerability Database
6.5 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
6.5 CVSS 3.1 Medium — — GitHub_M via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N (score shown at the top: nvd@nist.gov)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-444 · HTTP Request Smuggling

Other CVEs with this weakness →

CISA KEV details CISA

CISA lists a CVE once it has evidence of exploitation against real targets.

Listed
Sep 2, 2026
Federal deadline
Sep 16, 2026
passed 29 day(s) ago
Ransomware use
Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a reference date.

Public exploits, PoCs and detection templates

Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.

Detection templates (Nuclei)
Proofs of concept on GitHub

Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.

EPSS over time FIRST

Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 7.06%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Look for parameters with command/query metacharacters and unexpected child processes of the service.
  • Hunt retroactively in logs from before Sep 2, 2026 (KEV listing): exploitation may have started earlier.
web/proxy/WAF logsnetwork IDS/IPSapplication logsendpoint telemetry (EDR)

Timeline

What happened to this CVE, newest first.

  • 2026
  • Fix documented
    Oct 13, 2026 · GitHub Security Advisories
  • Affected products added · pip/starlette
    Oct 13, 2026 · GitHub Security Advisories
  • Affected products added · kludex/starlette
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 13, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 13, 2026
  • Fix documented
    Oct 13, 2026 · NIST National Vulnerability Database
  • Affected products added · encode/starlette, redhat/ai inference server, redhat/ansible automation platform, redhat/migration toolkit for applicati
    Oct 13, 2026 · NIST National Vulnerability Database
  • CVSS changed · 6.5
    Oct 13, 2026 · NIST National Vulnerability Database
  • Source status changed · → Analyzed
    Oct 13, 2026 · NIST National Vulnerability Database
  • Added to CISA KEV (detected)
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Record created in this database
    Oct 13, 2026 · CISA Known Exploited Vulnerabilities
  • Added to CISA KEV catalog
    Sep 1, 2026 · CISA
  • CVE published
    May 26, 2026 · GitHub_M

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 13, 2026 – Oct 13, 2026
  • 1× Official description updated · Oct 13, 2026 – Oct 13, 2026

References

31 on the record

Elsewhere on this site

Encode
every CVE for this vendor
2026-09
what else CISA listed that month
Injection
same class
CWE-444
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-12544 Foreman: ssti and insecure deserialization in foreman-rake configuration 14d
  • CVE-2026-12541 Foreman: command injection in foreman-rake database tasks 14d
  • CVE-2026-12540 Foreman: command injection in foreman-rake errors:fetch_log via request_id parameter 14d
  • CVE-2026-12423 Foreman: unauthenticated information disclosure via provisioning token validation flaw 14d
  • CVE-2026-81658 Foreman: cross-tenant disclosure of template revisions via unauthorized audit lookup Aug 27, 2026
  • CVE-2026-13316 Foreman: ssrf to cloud metada service through unvalidated test_url parameters in foreman config Jun 30, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-48710 is "Kludex Starlette HTTP Request/Response Smuggling Vulnerability", rated Medium. It affects Starlette (Encode); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 6.5 describes technical severity. EPSS 7.06% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

Comments

Moderated technical discussion. Read the community guidelines.

No comments yet.

Sign in or create an account to comment and suggest corrections.