Stack-based Buffer OverflowWeakness · CWE-121

CVE-2026-27671

CRITICAL · 9.8 CVSS v3.1 Published 2026-06-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Due to improper RFC protocol validation in the SAP Kernel used by the Application Server ABAP of SAP NetWeaver and ABAP Platform, an unauthenticated attacker can send a crafted RFC request that exploits logical errors in memory management, leading to memory corruption. This could lead to a high impact on the confidentiality, integrity, and availability of the application.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a memory corruption vulnerability in the SAP Kernel's RFC (Remote Function Call) protocol implementation. An unauthenticated attacker can send a specially crafted RFC request that exploits logical errors in memory management due to improper RFC protocol validation, leading to memory corruption and potential full system compromise.

MitigationApply the relevant SAP Kernel patches for the ABAP Application Server as soon as possible, and restrict network exposure of RFC interfaces to trusted sources since exploitation requires no authentication.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify SAP NetWeaver or ABAP Platform installation
    Check system for SAP NetWeaver or ABAP Platform installation directories and processes (e.g., saposcol, disp+work). Use transaction SM51 to list application server instances.
    Affected if System runs SAP NetWeaver or ABAP Platform Application Server ABAP
  2. Determine SAP Kernel version
    Execute 'disp+work -v' from the kernel directory or check the kernel version via SAP transaction SM51, then compare against SAP security notes for CVE-2026-27671.
    Affected if Kernel version matches the vulnerable version range announced by SAP
  3. Verify RFC functionality is enabled
    Check SAP transaction SM59 for defined RFC destinations and verify the RFC listener is active via transaction SMGW or command 'gwrd'.
    Affected if RFC functionality is enabled and the RFC gateway is active
  4. Assess RFC network exposure
    Review firewall rules and network configuration to determine if RFC ports (sapdp* and sapgw* services) are exposed to untrusted or external networks.
    Affected if RFC services are reachable from networks outside the trusted internal environment

Environment is affected if it runs a vulnerable SAP Kernel version where RFC functionality is enabled and accessible to unauthenticated network attackers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the relevant SAP Kernel patches for the ABAP Application Server as soon as possible, and restrict network exposure of RFC interfaces to trusted sources since exploitation requires no authentication.

Have this fixed Scoped from the published advisory
  • Consultation12.0 h
  • Implementation16.0 h
  • Testing24.0 h
  • Review / QA8.0 h
60.0 hours of engineering $10,320
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-27671 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-27671 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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