Cyber Resilience

CVE-2026-31251

High

Published: 11 May 2026

Published
11 May 2026
Modified
12 May 2026
KEV Added
Patch
CVSS Score v3.1 7.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
EPSS Score 0.0004 12.8th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-31251 is a high-severity Improper Input Validation (CWE-20) vulnerability in Notion (inferred from references). Its CVSS base score is 7.3 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Python (T1059.006); ranked at the 12.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

CosyVoice thru commit 6e01309e01bc93bbeb83bdd996b1182a81aaf11e (2025-30-21) contains an insecure deserialization vulnerability (CWE-502) in its gRPC server component. When the server starts, it loads the speech synthesis model from a user-specified directory using torch.load() without enabling the weights_only=True security parameter. This allows…

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the deserialization of arbitrary Python objects via the pickle module. An attacker can exploit this by providing malicious model files within a directory. When a victim starts the gRPC server pointing to this directory, arbitrary code is executed on the victim's system during server initialization.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1059.006 Python Execution
Adversaries may abuse Python commands and scripts for execution.
T1204.002 Malicious File Execution
An adversary may rely upon a user opening a malicious file in order to gain execution.
Why these techniques?

Insecure torch.load() deserialization of untrusted model files directly enables Python code execution (T1059.006) via malicious file supplied to victim (T1204.002).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

CVEs Like This One

CVE-2025-23304Shared CWE-94
CVE-2026-31253Shared CWE-94
CVE-2026-40156Shared CWE-94
CVE-2026-32640Shared CWE-915, CWE-94
CVE-2026-21268Shared CWE-20
CVE-2025-61982Shared CWE-94
CVE-2026-22807Shared CWE-94
CVE-2026-3476Shared CWE-94
CVE-2025-69872Shared CWE-94
CVE-2026-42214Shared CWE-94

Affected Assets

Notion
inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-20 CWE-94

Directly implements checks on information inputs to reject invalid data before processing.

addresses: CWE-20

Security testing and developer training directly verify and enforce proper input validation, reducing exploitability of injection and malformed-data weaknesses.

addresses: CWE-20

Security testing and evaluation at multiple SDLC stages directly detects missing or flawed input validation, with the required remediation process ensuring fixes are applied.

addresses: CWE-94

Makes persistent code injection into loaded programs impossible when the executable image itself resides on hardware-protected read-only media.

addresses: CWE-94

Dynamically generated code can be produced and executed inside the isolated chamber, preventing host compromise from code-injection payloads.

addresses: CWE-94

Directly prevents execution of attacker-supplied code written into data memory regions.

addresses: CWE-20

Spam protection mechanisms perform filtering and detection on inbound/outbound messages, directly compensating for missing or weak input validation of unsolicited content.

References