# CVE-2026-70388: Memory Corruption via Integer Underflow in Message Length Validation

Status: published. Published: 2026-10-26. Updated: 2026-11-02.

SOEM version 2.0.0 and earlier contains vulnerabilities where a malicious device on the network can send specially crafted messages that cause the master to write data outside allocated memory boundaries. The software performs arithmetic on message length values without proper validation, allowing negative or extremely large values to bypass safety checks. This can corrupt memory and potentially allow an attacker to execute arbitrary code on the master system.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- RT-Labs AB / SOEM: ≥ 0; < 2.0.1 (affected, semver). Source: CNA: ENISA

## Severity and prioritization

- CVSS 3.1: 8.3 (high); CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:H; source: CNA: ENISA

- CISA KEV: No listing in collected sources

- EPSS: 0.21% as of 2026-11-02; percentile 11.59%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-191, CWE-195, CWE-787

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://rt-labs.com/wp-content/uploads/2026/10/RRTL-260921-01.pdf (CNA: ENISA; vendor-advisory)

## Provenance

- CNA: ENISA: https://www.cve.org/CVERecord?id=CVE-2026-70388; retrieved 2026-11-02; source updated 2026-11-02

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-70388; retrieved 2026-11-02; source updated Not reported

Revision: 763d9087358b483338f98c0bfebc729815bdce51985bd92f186309b085e931f3

Canonical: https://y2.dev/cve/CVE-2026-70388

## Agent and API access

Public CVE pages, Markdown, and JSON are free to read without an account or API key.

- Public catalog: https://y2.dev/cve/index.json. Follow nextCursor with the same search, filters, sort, and limit (1–100). A null cursor marks the end.

- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

Collected public records only. Check source status for coverage and freshness.