SAP Approuter Vulnerable to HTTP Request Smuggling

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-27690: 0.68% estimated exploitation activity in the next 30 days; percentile 52.54 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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.

Published by the source

14 Jul 2026, 03:31 UTC

Last modified by the source

1 Sep 2026, 21:40 UTC

Source last checked

26 Oct 2026, 13:02 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-8m85-wqg7-c529

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-8m85-wqg7-c529

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-8m85-wqg7-c529

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# Patch Next advisory brief: CVE-2026-27690

Advisory: SAP Approuter Vulnerable to HTTP Request Smuggling
IDs: CVE-2026-27690, GHSA-8m85-wqg7-c529
Record: https://patchnext.com/advisories/cve-2026-27690 (revision 3, source checked 26 Oct 2026, 13:02 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @sap/approuter 20.10.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @sap/approuter: affected < 20.10.0; fixed in 20.10.0

## Suggested inspection (read-only)
- `npm ls @sap/approuter --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on @sap/approuter.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-8m85-wqg7-c529 (GitHub-reviewed advisory GHSA-8m85-wqg7-c529 lists affected ranges: npm @sap/approuter >=0 <20.10.0)
- Verified: https://osv.dev/vulnerability/GHSA-8m85-wqg7-c529 (OSV record GHSA-8m85-wqg7-c529 lists affected ranges: npm @sap/approuter >=0 <20.10.0 (fixed))

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