Cyber Resilience

CVE-2026-33587

Critical

Published: 07 May 2026

Published
07 May 2026
Modified
07 May 2026
KEV Added
Patch
CVSS Score v4 9.2 CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0023 13.8th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-33587 is a critical-severity Improper Input Validation (CWE-20) vulnerability in Lfnovo Open-Notebook. Its CVSS base score is 9.2 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 13.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and subsequently OS commands) on the docker container via Server-Side Template Injection (SSTI) for user-created transformations.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1059.006 Python Execution
Adversaries may abuse Python commands and scripts for execution.
Why these techniques?

SSTI in a web app directly enables remote code execution via Python (T1190 + T1059.006).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2026-33588Same product: Lfnovo Open-Notebook
CVE-2026-28201Same product: Lfnovo Open-Notebook
CVE-2025-48913Shared CWE-20
CVE-2025-67484Shared CWE-20
CVE-2026-4755Shared CWE-20
CVE-2026-23489Shared CWE-20
CVE-2025-54385Shared CWE-20
CVE-2026-48188Shared CWE-20
CVE-2026-22567Shared CWE-20
CVE-2026-26063Shared CWE-20

Affected Assets

lfnovo
open-notebook
≤ 1.8.4

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

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-20

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

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