Cyber Resilience

CVE-2026-103398

Path Traversal

Public PoCPath Traversal
Published
30 September 2026
Modified
30 September 2026
CVSS Score v4 8.6
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/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 0.0027 17th percentile
Risk Priority 39 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

Summary

CVE-2026-103398 is a high-severity External Control of File Name or Path (CWE-73) vulnerability. Its CVSS base score is 8.6 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data from Local System (T1005); ranked at the 17th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

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.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

OpenSave through 2.4.0 fails to properly validate save paths supplied by paired peers in the manifest request handler. Attackers can specify arbitrary directories outside configured save locations to read and write files through manifest and sync routes.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
T1083 File and Directory Discovery Discovery
Adversaries may enumerate files and directories or may search in specific locations of a host or network share for certain information within a file system.
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.
T1574.006 Dynamic Linker Hijacking Stealth
Adversaries may execute their own malicious payloads by hijacking environment variables the dynamic linker uses to load shared libraries.
T1574.007 Path Interception by PATH Environment Variable Stealth
Adversaries may execute their own malicious payloads by hijacking environment variables used to load libraries.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-8043Shared CWE-73
CVE-2025-3103Shared CWE-73
CVE-2026-72842Shared CWE-73
CVE-2026-19084Shared CWE-73
CVE-2024-0100Shared CWE-73
CVE-2026-85176Shared CWE-73
CVE-2025-65115Shared CWE-73
CVE-2026-33354Shared CWE-73
CVE-2026-27211Shared CWE-73
CVE-2026-5210Shared CWE-73

Affected Assets

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.3.2

Mitigating Controls (NIST 800-53 r5) AI

Enforces authorization checks on the actual resource accessed, blocking unauthorized files even when a malicious path is supplied.

Least-privilege limits the set of files or directories any subject can affect, shrinking the blast radius of a path-control flaw.

Input validation directly rejects or sanitizes untrusted path strings before they reach filesystem operations.

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.

PR.AA-05 partial match
prevents

Least-privilege file authorization directly limits damage from externally controlled paths.

PR.PS-06 partial match
prevents

Secure SDLC practices include input validation and path sanitization that eliminate this weakness.

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.

removes
removes
removes
removes
removes

References