CVE-2026-62652 Overview
CVE-2026-62652 affects Siemens Reyrolle 7SR5 protection relay devices running firmware versions prior to V2.70. The device firmware ships with binaries that retain debugging symbols, which should have been stripped before release. An unauthenticated attacker who downloads the publicly available firmware update files can use these symbols to accelerate reverse engineering of the device software. This weakness maps to [CWE-215: Insertion of Sensitive Information Into Debugging Code] and lowers the effort required to identify additional vulnerabilities in the platform.
Critical Impact
Retained debug symbols in publicly downloadable firmware expose function names, symbol tables, and structural metadata that assist adversaries in analyzing the Reyrolle 7SR5 device and discovering further weaknesses.
Affected Products
- Siemens Reyrolle 7SR5 (all versions prior to V2.70)
Discovery Timeline
- 2026-09-08 - CVE-2026-62652 published to NVD
- 2026-09-10 - Last updated in NVD database
Technical Details for CVE-2026-62652
Vulnerability Analysis
The Reyrolle 7SR5 is a digital protection relay used in electrical substation automation. Siemens distributes firmware update packages through publicly accessible channels so operators can maintain devices in the field. In versions before V2.70, the compiled binaries inside those update packages still contain debugging symbols. Debug symbols embed function names, variable names, source file references, and structural information that a stripped production binary would not disclose.
An attacker who obtains the firmware image can load it into a disassembler or decompiler and immediately see labeled functions and data structures. This shortens the analysis phase of vulnerability research against the device. The finding itself does not grant code execution or configuration access. It reduces the cost for an adversary preparing follow-on attacks against the relay firmware.
Root Cause
The root cause is a build and release process failure. Production firmware binaries were shipped without invoking a symbol-stripping step such as strip on ELF binaries or the equivalent toolchain flags. Debug metadata intended for internal engineering use remained in the release artifact.
Attack Vector
Exploitation begins with retrieval of the firmware update file from Siemens distribution channels. No authentication to the device is required, and no interaction with the device itself is needed to extract value from the symbols. The attacker performs offline static analysis of the extracted binaries. Any subsequently identified vulnerabilities would require their own attack path against a deployed relay.
Refer to the Siemens Security Advisory SSA-142885 for vendor-supplied technical detail.
Detection Methods for CVE-2026-62652
Indicators of Compromise
- No runtime indicators of compromise are associated with this issue, since exploitation is an offline reverse-engineering activity against downloaded firmware.
- Unusual download patterns of Reyrolle 7SR5 firmware update files from vendor portals may indicate reconnaissance interest.
Detection Strategies
- Inventory all Reyrolle 7SR5 devices and record their current firmware version to determine exposure against the V2.70 boundary.
- Monitor operational technology (OT) network segments for unexpected connections to protection relays that could follow reconnaissance based on symbol-derived intelligence.
- Correlate firmware download logs, where available, with known threat actor infrastructure targeting energy sector assets.
Monitoring Recommendations
- Enable centralized logging from substation gateways and jump hosts that provide access to Reyrolle 7SR5 management interfaces.
- Alert on new or unauthorized engineering workstation sessions targeting protection relays.
- Track vendor advisory updates from Siemens ProductCERT for supplemental fixes tied to advisory SSA-142885.
How to Mitigate CVE-2026-62652
Immediate Actions Required
- Upgrade Reyrolle 7SR5 firmware to V2.70 or later, which addresses the debug symbol exposure.
- Restrict access to management interfaces on protection relays to authorized engineering networks only.
- Review historical distribution of firmware images and treat prior versions as known-analyzable by adversaries.
Patch Information
Siemens has published fixed firmware in Reyrolle 7SR5 V2.70. Full remediation details and download references are provided in the Siemens Security Advisory SSA-142885.
Workarounds
- Apply defense-in-depth controls consistent with Siemens operational guidelines for substation automation, including network segmentation between IT and OT zones.
- Place Reyrolle 7SR5 devices behind firewalls and restrict inbound protocols to those strictly required for protection and control functions.
- Limit physical and logical access to engineering workstations that can communicate with the relays.
# Configuration example
# Verify installed Reyrolle 7SR5 firmware version through the device's
# engineering interface (DIGSI 5) and confirm it reports V2.70 or later.
# No command-line remediation is available; upgrade via the vendor-supplied
# firmware update procedure documented in Siemens advisory SSA-142885.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
