What is the CVSS score of EUVD-2026-55859?

EUVD-2026-55859 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.4%.

Which versions of SAP NetWeaver are affected by EUVD-2026-55859?

SAP NetWeaver ABAP servers running on internet-accessible systems are vulnerable to remote, unauthenticated memory corruption that can crash application servers or leak sensitive data.

How to fix or mitigate EUVD-2026-55859?

Within 24 hours: Identify all SAP NetWeaver ABAP instances accessible from untrusted networks and immediately apply firewall rules to restrict DIAG protocol access (ports 3200-3299) to only known, trusted IP ranges. Within 7 days: Implement network segmentation to isolate ABAP servers from internet-facing systems; enable SAP audit logging and configure intrusion detection for DIAG protocol traffic anomalies. Within 30 days: Monitor SAP Security Patch Day for an available vendor fix; conduct a full assessment of affected ABAP systems, coordinate patch testing with business units, and establish a phased deployment schedule.

SAP NetWeaver EUVD-2026-55859

| CVE-2026-34265 CRITICAL

Out-of-bounds Write (CWE-787)

2026-08-11 sap

GHSA-f774-9w9m-r939

Buffer Overflow Memory Corruption SAP Sap Netweaver And Abap Platform Sap Se

9.8

CVSS 3.1 · Vendor: sap

Severity by source

Vendor (sap) PRIMARY

9.8 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

vuln.today AI

9.8 CRITICAL

Unauthenticated remote DIAG parsing bug (AV:N/AC:L/PR:N/UI:N); out-of-bounds write supports A:H and C:H, with I:H retained on worst-case memory-corruption potential though the description mainly demonstrates disclosure and crash.

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

4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (sap).

CVSS VectorVendor: sap

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Aug 11, 2026 - 01:00 vuln.today

CVE Published

Aug 11, 2026 - 00:10 cve.org

CRITICAL 9.8

DescriptionCVE.org

SAP NetWeaver Application Server ABAP allows an unauthenticated attacker to exploit logical errors in DIAG protocol parsing, resulting in memory corruption. This vulnerability could potentially disclose sensitive system information or crash the system, leading to a high impact on the confidentiality, integrity, and availability of the application.

Articles & Coverage 1

News Critical Memory Corruption in SAP NetWeaver AS ABAP DIAG Protocol - CVE-2026-34265 Aug 11, 2026

AnalysisAI

Memory corruption in SAP NetWeaver Application Server ABAP lets an unauthenticated, remote attacker abuse logical flaws in the proprietary DIAG protocol parser to overwrite out-of-bounds memory, potentially leaking sensitive system data or crashing the ABAP work processes. The flaw carries a CVSS 9.8 (AV:N/AC:L/PR:N/UI:N) and is classified CWE-787 (out-of-bounds write); it was disclosed and patched by SAP via a monthly Security Patch Day note. There is no public exploit identified at time of analysis, and it is not listed in CISA KEV.

Technical ContextAI

The affected component is the DIAG (Dynamic Information and Action Gateway) protocol, the proprietary presentation-layer protocol SAP uses between the SAP GUI thick client and the ABAP application server's dispatcher/work processes, typically served on TCP ports 32NN (e.g. 3200). The vulnerability is CWE-787 (out-of-bounds write): logical errors while parsing attacker-supplied DIAG protocol structures cause the server to write outside intended buffer boundaries, corrupting adjacent memory. Because DIAG framing and field-length handling are performed by the server before any user is authenticated, malformed length or type fields in the parse path can drive the corruption. The CPE cpe:2.3:a:sap_se:sap_netweaver_and_abap_platform indicates the SAP NetWeaver and ABAP Platform application-server stack is the affected product family.

RemediationAI

Apply the fix delivered in SAP security note 3714806 (https://me.sap.com/notes/3714806) as part of the corresponding SAP Security Patch Day (https://url.sap/sapsecuritypatchday) - this is a kernel/SAP_BASIS level correction, so plan for the associated kernel or support-package update and a restart of the affected application servers; exact patched levels are enumerated in the note. Patch available per vendor advisory (no discrete fix version is provided in the input, so cite the note rather than inventing a version). Where immediate patching is not possible, reduce exposure to the DIAG dispatcher: restrict network reachability of the SAP GUI/DIAG ports (typically TCP 32NN, e.g. 3200) so they are reachable only from trusted admin/GUI subnets via firewall or host ACLs, and front-end DIAG access with SAProuter and SNC so unauthenticated raw connections from untrusted networks are blocked - the trade-off is that any legitimate SAP GUI users on excluded networks lose direct connectivity and must route through the approved gateway. Do not expose DIAG ports to the internet under any circumstance.