CVE-2026-2331
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-2331 is a critical-severity Files or Directories Accessible to External Parties (CWE-552) vulnerability in Sick (inferred from references). Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked in the top 44% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and AC-6 (Least Privilege) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-2331 is a vulnerability in the AppEngine Fileaccess feature over HTTP, stemming from improper access restrictions (CWE-552). A critical filesystem directory is unintentionally exposed, enabling unauthenticated read and write operations on sensitive areas. This affects SICK products utilizing the AppEngine environment, including device parameter files and custom application directories. The issue carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and was published on 2026-03-06.
Any unauthenticated attacker with network access can exploit this vulnerability. Successful exploitation allows reading and modifying application settings, such as customer-defined passwords stored in device parameter files. Additionally, exposure of the custom application directory permits execution of arbitrary Lua code within the sandboxed AppEngine environment, potentially leading to full compromise of affected devices.
SICK has issued advisories detailing mitigation, available in CSAF format at sca-2026-0006.json and the corresponding PDF. Additional guidance appears in SICK's operating guidelines for cybersecurity. General ICS recommended practices from CISA may also apply.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-10025
Vulnerability Data
An attacker may perform unauthenticated read and write operations on sensitive filesystem areas via the AppEngine Fileaccess over HTTP due to improper access restrictions. A critical filesystem directory was unintentionally exposed through the HTTP-based file access feature, allowing access without…
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authentication. This includes device parameter files, enabling an attacker to read and modify application settings, including customer-defined passwords. Additionally, exposure of the custom application directory may allow execution of arbitrary Lua code within the sandboxed AppEngine environment.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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- 5 hardening rules · 2 OS baselines
V8.4.2
Mitigating Controls (NIST 800-53 r5) AI
AC-3 directly enforces authorization checks on access to files and directories, stopping unauthorized external exposure.
AC-6 limits granted privileges, reducing the chance that files or directories become reachable by external parties.
AC-4 enforces information flow rules that can block unauthorized external access to files or directories.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Enforcing least-privilege permissions and authorization policies directly prevents unauthorized file/directory exposure.
Logical segmentation and access protections stop external parties from reaching files that should remain internal.
Data-at-rest protections such as encryption or ACLs reduce the impact of unintended file exposure.
Hardened configuration baselines commonly include file-system permission settings that limit external access.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
By tracing and retrieving all copies of information stored on endpoint and portable devices, the control reduces the likelihood that files remain accessible outside the organization’s security perimeter.
Labeling information according to its sensitivity and specifying corresponding protection measures makes it less probable that files or directories containing sensitive content will be left accessible to external parties.
Including asset location and ownership in the inventory, combined with secure disposal procedures, decreases the chance that files or directories remain accessible to external parties after they should have been removed or restricted.
Solid perimeters and locked external access points stop files, devices, or directories containing sensitive data from being reachable by external parties who could otherwise walk in or break in.
Authorizing and logging the removal of storage media, disabling unused ports, and monitoring transfers limit the exposure of files or directories to external parties outside the organization’s controlled environment.
Segregating delivery/loading zones and controlling external doors prevents external parties from reaching directories or resources that should remain inaccessible.
Hardening callouts derived
Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).
Oracle Linux 8 (2 rules)
- V-248579 OL 8 must restrict access to the kernel message buffer. prevents CWE-552
- V-248597 There must be no "shosts.equiv" files on the OL 8 operating system. prevents CWE-552