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NVD / CVE Program· CNA GitHub_M

CVE-2026-48710: Starlette has missing Host header validation that poisons request.url.path, bypassing path-based security checks

Noroxi assessment

Priority: This week (action score 77/100)

  • CISA has confirmed exploitation in the wild (Sep 2, 2026). Remediation deadline for US federal agencies: Sep 16, 2026.
  • A ready-made attack module is public (Nuclei); exploiting it takes no special expertise.
  • Probability of exploitation in the next 30 days: 70.2% (FIRST EPSS); higher than 99.3% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: starlette (Debian:12) 0.26.1-1+deb12u1; starlette (Debian:13) 0.46.1-3+deb13u2; starlette (Debian:14) 1.1.0-1.

Don’t wait for the next maintenance window. Upgrade to starlette (Debian:12) 0.26.1-1+deb12u1; starlette (Debian:13) 0.46.1-3+deb13u2; starlette (Debian:14) 1.1.0-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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.

MediumCVSS 6.5 · v3.1KEVWeaponized Fix available
Published
May 26, 2026
Updated
Oct 1, 2026
EPSS
70.2% · 99th percentile

Report tools

JSON

Action score

77

This week

Don’t wait for the next maintenance window.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
30 / 30 · Listed
EPSS
21 / 30 · 70.2%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
6.5
CNA · GitHub_M
6.5
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Sep 2, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Sep 16, 2026.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-48710

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
encodestarlette
redhatai inference server
redhatansible automation platform
redhatmigration toolkit for applications
redhatopenshift ai
redhatopenshift lightspeed
redhatsatellite
redhatenterprise linux ai

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • encode starlette0.8.3 and later · before 1.0.1
  • redhat ai inference server3.3.0 and later · up to 3.3.5 inclusive
  • redhat ansible automation platform2.6
  • redhat ansible automation platform2.7
  • redhat enterprise linux ai3.0
  • redhat migration toolkit for applicationsbefore 8.2.0
  • redhat openshift ai3.4 and later · before 3.4.2
  • redhat openshift ai3.3 and later · before 3.3.5
  • redhat openshift lightspeedall versions
  • redhat satellite6.17
  • redhat satellite6.18
  • redhat satellite6.19

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • Kludex starlette

    • < 1.0.1affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12starlettebefore 0.26.1-1+deb12u10.26.1-1+deb12u1
Debian:13starlettebefore 0.46.1-3+deb13u20.46.1-3+deb13u2
Debian:14starlettebefore 1.1.0-11.1.0-1
openSUSE:Leap 16.0python-starlettebefore 0.41.3-160000.3.10.41.3-160000.3.1
openSUSE:Tumbleweedpython-google-adkbefore 2.2.0-1.12.2.0-1.1
openSUSE:Tumbleweedpython-starlettebefore 1.2.0-1.11.2.0-1.1
PyPIstarlettebefore 1.0.11.0.1
SUSE:Linux Enterprise Server 16.0python-starlettebefore 0.41.3-160000.3.10.41.3-160000.3.1

Same product

encode: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-47874Starlette Denial of service (DoS) via multipart/form-data
    34Monitor
  • CVE-2023-29159Directory traversal vulnerability in Starlette versions 0.13.5 and later and prior to 0.27.0 allows a remote unauthenticated attacker to vie
    31Monitor
  • CVE-2026-54283Starlette: request.form() limits silently ignored for application/x-www-form-urlencoded enable DoS
    30Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2023-30798Apr 21, 2023 · MultipartParser DOS with too many fields or files in Starlette Framework
    30Monitor
  • ← EarlierCVE-2025-54121Jul 21, 2025 · Starlette has possible denial-of-service vector when parsing large files in multipart forms
    21Monitor
  • Later →CVE-2026-48818Jun 17, 2026 · Starlette: SSRF and NTLM credential theft via UNC paths in StaticFiles on Windows
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:starlette0.26.1-1+deb12u1 · Debian:12Package registry (OSV)
opensuse:python-google-adk2.2.0-1.1 · openSUSE:TumbleweedPackage registry (OSV)
opensuse:python-starlette1.2.0-1.1 · openSUSE:TumbleweedPackage registry (OSV)
PyPI:starlette1.0.1Package registry (OSV)
suse:python-starlette0.41.3-160000.3.1 · SUSE:Linux Enterprise Server 16.0Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Nuclei detection template ×2
  • Proof-of-concept repository on GitHub ×5

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Nuclei detection templateNuclei template CVE-2026-42271 —
Nuclei detection templateNuclei template CVE-2026-48710 —
Proof-of-concept repository on GitHubstars:32026-04-01
Proof-of-concept repository on GitHubstars:12026-05-27
Proof-of-concept repository on GitHubstars:12026-05-28
Proof-of-concept repository on GitHubstars:02026-08-03
Proof-of-concept repository on GitHubstars:02026-08-11

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-56 d
  2. Published
  3. CISA KEV+98 d
  4. TodayNov 2, 2026+160 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
low · data can be read
Integrity
low · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
Low
Integrity impact
Low
Availability impact
None

Weakness class (CWE)

CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (19 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records