SAP September 2026 Security Update Fixes 4 Critical Vulnerabilities and 15 Other Flaws
SAP's September 2026 Patch Tuesday ships 19 security notes, including four criticals led by a CVSS 10.0 memory-corruption flaw in Extended Passport Processing.
Deserialization flaw allows local code execution in SAP NetWeaver Business Client
SAP NetWeaver Business Client does not sufficiently validate certain locally stored data that it processes at application startup, a flaw classified as CWE-502 (deserialization of untrusted data). An attacker with low privileges on the local system can replace this data with specially crafted content, and when the application is next launched the crafted content is processed with no further user interaction required. Successful exploitation results in arbitrary code execution in the context of the logged-on user, with high impact on the confidentiality, integrity, and availability of the application. Any organization running the SAP NetWeaver Business Client desktop application is affected, and fixes were delivered as part of SAP's September 2026 Security Patch Day. No public proof-of-concept, CISA KEV listing, or confirmed in-the-wild exploitation is known, and EPSS currently estimates only a 0.2% probability of exploitation within 30 days.
What to do: Apply the SAP security patch released with the September 2026 Patch Day to all systems running SAP NetWeaver Business Client, checking SAP's advisory for the specific affected and corrected releases. Because exploitation requires low-privileged local access, limit write access to the application's locally stored data/configuration locations and maintain endpoint hardening on workstations running the client. No workarounds are described in the available data, so prompt patching is the primary remediation.
| Product | Affected |
|---|---|
| SAP NetWeaver Business Client | — |
Order-of-magnitude estimate by the model from install counts, market share and public scan data it knows; verify before quoting.
SAP NetWeaver Business Client does not perform sufficient validation when processing certain locally stored data during application startup. An attacker with low privileges on the local system could replace this data with specially crafted content. When the application is next launched, the crafted content is processed and could lead to arbitrary code execution in the context of the user. This results in a high impact on confidentiality, integrity and availability of the application.
SAP's September 2026 Patch Tuesday ships 19 security notes, including four criticals led by a CVSS 10.0 memory-corruption flaw in Extended Passport Processing.
SAP's September 2026 Patch Day fixes 19 notes including CVE-2026-44756 (CVSS 10.0), unauthenticated memory corruption in SAP Extended Passport Processing kernels.
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