# CVE-2026-62645: Siemens Reyrolle 7SR5 session ID prediction in web interface

Source: https://junglewise.ai/threats/cve-2026-62645-siemens-reyrolle-7sr5-session-id-prediction-in-web-interface  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-62645 · Severity: critical · CVSS 9.8 · Published 2026-09-08

Reyrolle 7SR5 is an electrical substation protection and automation device that provides critical control functions for power grids. A vulnerability in its web interface exposes information that allows attackers to predict session IDs and bypass authentication, gaining full unauthorized access to device configuration and operations without requiring valid credentials.

Technologies: [Siemens Reyrolle 7SR5](https://junglewise.ai/threats/technologies/reyrolle-7sr5). Vendors: [Siemens](https://junglewise.ai/threats/vendors/siemens).

## Quick answers

**Is CVE-2026-62645 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-62645 being exploited in the wild.

**How severe is CVE-2026-62645?** Critical severity, with a CVSS score of 9.8, published 8 September 2026.

**Which products and versions are affected?** Siemens Reyrolle 7SR5 all versions before V2.70.

**Is there a fix for CVE-2026-62645?** A patch was published on 2026-09-08: Update to V2.70 or later Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-62645 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-62645?** Check whether you run Siemens Reyrolle 7SR5 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

CVE-2026-62645 is an information disclosure vulnerability in Reyrolle 7SR5 web interface that exposes data enabling calculation of current and past session ID numbers. The vulnerability results from insufficient entropy in session identifier generation combined with information leakage through the web interface. An unauthenticated attacker on the network can access the web interface, extract exposed information, and derive valid session tokens to bypass authentication. This allows complete unauthorized access to device management and control functions. The vulnerability affects all versions before V2.70; the vendor has released a patch and recommends immediate update.

## Affected products

- Siemens Reyrolle 7SR5 all versions before V2.70

## Timeline

- 2026-09-08: disclosed
- 2026-09-08: patched: Update to V2.70 or later

## References

- [https://cert-portal.siemens.com/productcert/html/ssa-142885.html](https://cert-portal.siemens.com/productcert/html/ssa-142885.html)

## Related threats

- [Siemens Reyrolle 7SR5 unsigned code execution in maintenance mode](https://junglewise.ai/threats/cve-2026-62654-siemens-reyrolle-7sr5-unsigned-code-execution-in-maintenance-mode)
- [Siemens Reyrolle 7SR5 memory corruption in firmware-update protocol](https://junglewise.ai/threats/cve-2026-62653-siemens-reyrolle-7sr5-memory-corruption-in-firmware-update)
- [Siemens Reyrolle 7SR5 unstripped debug symbols in firmware](https://junglewise.ai/threats/cve-2026-62652-siemens-reyrolle-7sr5-unstripped-debug-symbols-in-firmware)
- [Siemens Reyrolle 7SR5 privilege escalation via RBAC bypass](https://junglewise.ai/threats/cve-2026-62650-siemens-reyrolle-7sr5-privilege-escalation-via-rbac-bypass)
- [Siemens Reyrolle 7SR5 denial-of-service via resource exhaustion](https://junglewise.ai/threats/cve-2026-62649-siemens-reyrolle-7sr5-denial-of-service-via-resource-exhaustion)