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CWE-444Weakness · CWE-444

CVE-2026-27690

CRITICAL · 9.1 CVSS v3.1 Published 2026-07-14
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 6 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Due to an HTTP Request Smuggling vulnerability in SAP Approuter, an unauthenticated attacker could send a specially crafted HTTP request that leads to request-response desynchronization. This could result in the exposure of user responses and cause the system to become unavailable. This leads to a high impact on confidentiality and availability.

In the news

Third-party coverage
Trending covered by 4 outlets this week · latest 1mo ago

Surfaced from public web coverage — external links open in a new tab.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

HTTP Request Smuggling vulnerability in SAP Approuter allows an unauthenticated attacker to send specially crafted HTTP requests that cause desynchronization between frontend and backend servers. This request-response desynchronization enables exposure of user session data through response hijacking and can render the system unavailable.

MitigationApply SAP security patches for Approuter when available; review frontend proxy configurations to ensure consistent request parsing across all gateway components.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Locate SAP Approuter installation
    Identify the directory where SAP Approuter is deployed. Common locations include the application root folder in Cloud Foundry environments or the server's webapp directory. Look for files such as package.json, xs-app.json, or manifest.yml that are typical SAP Approuter artifacts.
    Affected if SAP Approuter is present in the environment
  2. Determine installed Approuter version
    Check the version by examining the package.json file in the Approuter directory for the @sap/approuter dependency version, or run the command 'npm list @sap/approuter' in the Approuter directory if npm is available.
    Affected if The installed version is lower than the patched version (compare against SAP security notes)
  3. Verify Approuter is network-exposed
    Review network configuration, Cloud Foundry routes, or reverse proxy settings to confirm the Approuter is accessible via HTTP/HTTPS from external sources or untrusted networks.
    Affected if The Approuter has an exposed HTTP endpoint that accepts incoming requests
  4. Inspect HTTP request handling configuration
    Examine the Approuter's xs-app.json or any custom middleware configuration to understand how HTTP requests are processed and whether request parsing could be manipulated.
    Affected if The configuration allows raw or non-normalized HTTP requests to reach the Approuter backend
  5. Check for existing security patches
    Review SAP security notes or the Approuter's changelog for mentions of HTTP Request Smuggling fixes, and verify whether the currently installed version includes protections against request desynchronization.
    Affected if No HTTP Request Smuggling fix has been applied to the installed version

The environment is affected if SAP Approuter is running an unpatched version and is exposed to HTTP traffic, allowing specially crafted requests to trigger request-response desynchronization.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply SAP security patches for Approuter when available; review frontend proxy configurations to ensure consistent request parsing across all gateway components.

Have this fixed Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing12.0 h
  • Review / QA6.0 h
30.0 hours of engineering $5,120
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $8,192.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27690 in production — separate from our analysis above.

No notes yet

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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