What is CVE-2026-66778?

CVE-2026-66778 is a medium-severity vulnerability in SAP Approuter, classified under Improper Neutralization of HTTP Headers for Scripting Syntax. CVSS score: 5.3/10. Published 2026-08-11.

How severe is CVE-2026-66778?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in SAP Approuter

CVE-2026-66778

SAP Approuter does not sufficiently sanitize certain request headers before forwarding traffic to internal components. An unauthenticated attacker could send a specially crafted request to obtain limited unauthorized access to information. This results in a low impact on confidentiality. There is no impact on integrity and availability.

Published 2026-08-11 · last modified 2026-09-08.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.004 (26.9th percentile), scored 2026-09-26.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.001

Affected products

SAP Approuter
SAP Se Business Ai Platform (Approuter) — versions SAP Approuter node.js package < 23.0.0

Weakness classification (CWE)

CWE-644 — Improper Neutralization of HTTP Headers for Scripting Syntax

References

me.sap.com/notes/3786038 (Permissions Required)
url.sap/sapsecuritypatchday (Vendor Advisory)

Frequently asked questions

What is CVE-2026-66778?: CVE-2026-66778 is a medium-severity vulnerability in SAP Approuter, classified under Improper Neutralization of HTTP Headers for Scripting Syntax. CVSS score: 5.3/10. Published 2026-08-11.
How severe is CVE-2026-66778?: Medium severity. CVSS v3 base score is 5.3 out of 10.