CVE-2026-27663

Denial of Service via Resource Exhaustion in Siemens CPCI85 and RTUM85

Published Mar 26, 2026 CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed
Description
A vulnerability has been identified in CPCI85 Central Processing/Communication (All versions < V26.10), RTUM85 RTU Base (All versions < V26.10). The affected application contains denial-of-service (DoS) vulnerability. The remote operation mode is susceptible to a resource exhaustion condition when subjected to a high volume of requests. Sending multiple requests can exhaust resources, preventing parameterization and requiring a reset or reboot to restore functionality.

Analysis

AI-generated

Technical impact

A denial‑of‑service vulnerability has been identified in the remote operation mode of Siemens CPCI85 Central Processing/Communication and RTUM85 RTU Base. The flaw allows an attacker to flood the device with a high volume of requests, exhausting internal resources such as memory or processing queues, which in turn prevents the proper handling of legitimate requests and forces the device to reset or reboot to regain functionality. The weakness is classified as resource exhaustion (CWE-770).

Affected Systems

Siemens CPCI85 Central Processing/Communication (all versions prior to V26.10) and Siemens RTUM85 RTU Base (all versions prior to V26.10) are affected. Only these pre‑V26.10 builds are vulnerable; newer releases are presumed fixed.

Risk and Exploitability

The CVSS score of 7.1 indicates a moderate to high impact that is feasible for remote exploitation; no authentication is required and the attacker only needs the ability to send repeated requests to the target. EPSS data is not available, and the vulnerability is not listed in the CISA KEV catalog, suggesting exploitation may be uncommon but still plausible, especially in environments where the remote operation mode is exposed without adequate controls. Unauthorized remote attackers can induce service disruption without affecting confidentiality or integrity of the device’s configuration.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update to firmware version V26.10 or later for CPCI85 and RTUM85 as released by Siemens.
  • Restrict network access to the remote operation interface to authorized systems only.
  • Implement rate limiting or firewall rules to throttle excessive request traffic toward the device.
  • If a patch is not immediately available, consider disabling the remote operation mode or isolating the device from the network.

Generated by OpenCVE AI on March 26, 2026 at 15:57 UTC.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Denial of Service via Resource Exhaustion in Siemens CPCI85 and RTUM85
Type Values Removed Values Added
First Time appeared Siemens
Siemens cpci85 Central Processing\/communication
Siemens rtum85 rtu Base
Vendors & Products Siemens
Siemens cpci85 Central Processing\/communication
Siemens rtum85 rtu Base
Type Values Removed Values Added
Description A vulnerability has been identified in CPCI85 Central Processing/Communication (All versions < V26.10), RTUM85 RTU Base (All versions < V26.10). The affected application contains denial-of-service (DoS) vulnerability. The remote operation mode is susceptible to a resource exhaustion condition when subjected to a high volume of requests. Sending multiple requests can exhaust resources, preventing parameterization and requiring a reset or reboot to restore functionality.
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling

Sources

Status
PUBLISHED
Assigner
siemens
Published
Updated
Apr 14, 2026, 6:24 PM
Reserved
Feb 23, 2026, 10:07 AM
Status
Awaiting Analysis
Published
Mar 26, 2026, 3:16 PM
Modified
Jun 17, 2026, 10:27 AM