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Out-of-bounds WriteWeakness · CWE-787

CVE-2026-27664

HIGH · 7.5 CVSS v3.1 Published 2026-03-26
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
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
A vulnerability has been identified in CPCI85 Central Processing/Communication (All versions < V26.10), SICORE Base system (All versions < V26.10.0). The affected application contains an out-of-bounds write vulnerability while parsing specially crafted XML inputs. This could allow an unauthenticated attacker to exploit this issue by sending a malicious XML request, which may cause the service to crash, resulting in a denial-of-service condition.

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 · moderate confidence

Out-of-bounds write vulnerability in XML parsing in CPCI85 Central Processing/Communication (versions < V26.10) and SICORE Base system (versions < V26.10.0). An unauthenticated attacker can send specially crafted malicious XML requests to crash the service, causing denial of service.

MitigationUpdate to version V26.10 (CPCI85) or V26.10.0 (SICORE) or later to obtain the vendor patch. Additionally, implement XML input validation and consider restricting XML parser permissions to limit write operations.

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
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 installed CPCI85 version
    Locate the CPCI85 Central Processing/Communication application and retrieve its version information, typically found in the application properties, about dialog, or version file shipped with the installation
    Affected if version is below V26.10
  2. Identify installed SICORE version
    Locate the SICORE Base system application and retrieve its version information, typically found in the application properties, about dialog, or version file shipped with the installation
    Affected if version is below V26.10.0
  3. Confirm XML parsing is in use
    Check if XML parsing functionality is enabled or actively used by the application. Review configuration files or runtime settings that control XML request processing
    Affected if XML parsing feature is enabled or configured to accept incoming requests
  4. Verify network exposure
    Determine whether the XML parsing service is exposed to network connections. Check firewall rules, listening ports, and service binding configurations to see if unauthenticated external requests can reach the XML parser
    Affected if the service accepts external XML requests from untrusted sources

You are affected if either CPCI85 is below V26.10 or SICORE is below V26.10.0 AND the XML parsing feature is enabled and accessible to 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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to version V26.10 (CPCI85) or V26.10.0 (SICORE) or later to obtain the vendor patch. Additionally, implement XML input validation and consider restricting XML parser permissions to limit write operations.

Recommended fix Moderate confidence

CPCI85 to V26.10 or later; SICORE Base system to V26.10.0 or later

  1. 1. Identify all deployed instances of CPCI85 Central Processing/Communication and SICORE Base system in the environment.
  2. 2. Check current version numbers of affected installations.
  3. 3. Obtain the fixed versions (V26.10 for CPCI85, V26.10.0 for SICORE Base system) from the official Siemens software distribution channels or Siemens support.
  4. 4. Schedule a maintenance window for the upgrade.
  5. 5. Back up current configurations and data.
  6. 6. Apply the upgrade to CPCI85 to version V26.10 or later.
  7. 7. Apply the upgrade to SICORE Base system to version V26.10.0 or later.
  8. 8. Verify the services start successfully after upgrade.

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
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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-2026-27664 in production — separate from our analysis above.

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  • Version or environment caveats, and links to real fixes
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