How severe is CVE-2026-27690?

CVE-2026-27690 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.

Is CVE-2026-27690 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-27690?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2026-27690 published?

CVE-2026-27690 was published on 2026-07-14.

CVE-2026-27690

CVE-2026-27690 is a critical-severity vulnerability with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-444.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (50th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-444
Published: 2026-07-14
Last modified: 2026-07-14

Description

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.

Frequently asked questions

What is CVE-2026-27690?: 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.
How severe is CVE-2026-27690?: CVE-2026-27690 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
Is CVE-2026-27690 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (50th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-27690?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2026-27690 published?: CVE-2026-27690 was published on 2026-07-14.

References

Other CWE-444 (HTTP Request/Response Smuggling) vulnerabilities

CVE-2026-58150 — Critical (CVSS 10.0): Apache Traffic Server does not reject Transfer-Encoding in HTTP/2 requests, allowing downgrade request smuggling. This…
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CVE-2025-1867 — Critical (CVSS 10.0): Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in ithewei libhv allows…
CVE-2022-22536 — Critical (CVSS 10.0): SAP NetWeaver Application Server ABAP, SAP NetWeaver Application Server Java, ABAP Platform, SAP Content Server 7.53…
CVE-2018-3907 — Critical (CVSS 10.0): An exploitable vulnerability exists in the REST parser of video-core's HTTP server of the Samsung SmartThings Hub…
CVE-2025-55315 — Critical (CVSS 9.9): Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an authorized…

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