CVE-2025-11839 Siemens CVE debrief

Who should care

OT and plant security teams, Siemens SIMATIC S7-1500 operators, system integrators, and administrators who allow local or interactive access to the affected devices or their GNU/Linux subsystem.

Technical summary

The supplied record assigns CVE-2025-11839 to five Siemens SIMATIC S7-1500 CPU family product variants. The CVE description characterizes the flaw as a local manipulation issue in GNU Binutils 2.45 affecting tg_tag_type in prdbg.c, leading to an unchecked return value; the published CVSS vector is AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L (3.3). In the advisory corpus, the practical impact is limited to availability, with no confidentiality or integrity impact stated, and Siemens lists no available fix at the time of publication.

Defensive priority

Medium. The issue requires local access and is scored low, but it affects OT hardware, the source notes a public exploit, and the advisory says no fix is available.

Recommended defensive actions

• Restrict interactive shell access on affected devices to trusted personnel only.
• Only build and run applications from trusted sources on affected systems.
• Inventory the affected Siemens SIMATIC S7-1500 CPU model variants and confirm where they are deployed.
• Apply least-privilege access and segmentation around the affected OT assets to reduce local exposure.
• Track Siemens ProductCERT and CISA advisory updates for any future remediation guidance.
• Review local user accounts and operational workflows that could provide untrusted access to the device or its GNU/Linux subsystem.

Evidence notes

Primary evidence comes from the supplied CISA CSAF advisory ICSA-25-162-05 and its Siemens ProductCERT references. That corpus ties CVE-2025-11839 to the Siemens SIMATIC S7-1500 CPU family, lists five affected product identifiers, and states that no fix is available. The CVE description text also mentions GNU Binutils 2.45, prdbg.c, tg_tag_type, a local attack path, and a publicly released exploit. The advisory corpus does not further explain the component mapping between the GNU Binutils description and the Siemens product scope, so that linkage should be treated cautiously.

Official resources