CVE-2026-27690: Due to an HTTP Request Smuggling vulnerability in SAP Approuter, an unauthenticated attacker could send a spec

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CRITICAL 9.1REMOTEUPGRADE

CVE-2026-27690 is a critical-severity flaw (CVSS 9.1) affecting approuter. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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.

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 48%)
CISA exploited list	No
Weakness	CWE-444
Published	2026-07-14
Last modified	2026-10-24

Publisher (CNA): SAP SE · Vendor: sap

Last updated 2026-10-24 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-07-14 01:16 UTCPublished CVE record published
2026-10-24 22:10 UTCUpdated Record last modified

sap approuter UPGRADE

Affected: < 20.10.0

Fixed in: 20.10.0

Safe to downgrade to: no unaffected older release

1. Check installed version

npm ls approuter

2. UPGRADE to 20.10.0

npm install approuter@">=20.10.0"

Exact fixes by distribution

npm · @sap/approuter · FIXED · 20.10.0 · vulnerable: < 20.10.0 · source

npm install @sap/approuter@">=20.10.0" npm ls @sap/approuter

Fedora 46 · perl-Alien-Brotli · FIXED · 0.2.2-16.fc46 · FEDORA-2026-a2abe3db79 · source

sudo dnf upgrade --advisory=FEDORA-2026-a2abe3db79

Fedora ELN · mariadb-connector-odbc · FIXED · 3.2.10-1.eln159 · FEDORA-2026-b481dcd597 · source

sudo dnf upgrade --advisory=FEDORA-2026-b481dcd597

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-27690?

approuter: upgrade to 20.10.0. Exact commands for each OS are on this page.

Is CVE-2026-27690 being exploited?

CVE-2026-27690 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-27690 affect?

CVE-2026-27690 affects approuter. Severity is critical (CVSS 9.1). 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 a

How urgent is CVE-2026-27690?

Priority 53/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action

Software pages

SAP vulnerabilities

Related CVEs

CVE-2026-44745 HIGH 8.1 UPGRADE SAP Approuter does not properly validate incoming request headers during the OAuth2 login flow under certain c
CVE-2026-58230 HIGH 7.0 UPGRADE SAP Approuter does not sufficiently validate certain token content under specific configurations
CVE-2026-58238 MEDIUM 5.9 UPGRADE SAP Approuter does not sufficiently handle certain requests under specific conditions
CVE-2026-66778 MEDIUM 5.3 UPGRADE SAP Approuter does not sufficiently sanitize certain request headers before forwarding traffic to internal com
CVE-2026-66777 MEDIUM 5.9 UPGRADE SAP Approuter does not sufficiently validate certain incoming requests before forwarding them to backend desti

References

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