Raw vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/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:XCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2026-39859 is a medium-severity Path Traversal (CWE-22) vulnerability in Liquidjs Liquidjs. Its CVSS base score is 6.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 37th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to AC-3 (Access Enforcement) and SI-10 (Information Input Validation) — 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-2026-39859 is a path traversal vulnerability (CWE-22) in LiquidJS, a pure JavaScript template engine compatible with Shopify and GitHub Pages. The issue affects versions prior to 10.25.3, where the documented root directory constraint for filenames passed to renderFile() and parseFile() is not enforced during top-level file loads. This allows an attacker to bypass the root boundary when a Liquid instance is configured with an empty temporary directory as root, enabling the disclosure of arbitrary file contents on the server.
The vulnerability has a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N), indicating it is exploitable remotely with low complexity and no privileges or user interaction required. An unauthenticated attacker who can influence file paths processed by a vulnerable LiquidJS instance—such as through user-supplied templates or inputs in a web application—can achieve arbitrary file read access, potentially exposing sensitive data like configuration files, source code, or credentials.
The GitHub security advisory (GHSA-v273-448j-v4qj) confirms the vulnerability and states it is fixed in LiquidJS version 10.25.3, recommending immediate upgrades for all affected installations. No workarounds are detailed beyond ensuring proper root directory configuration and validating inputs, with practitioners advised to review deployments using LiquidJS in server-side rendering contexts.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-20611
Vulnerability Data
LiquidJS is a Shopify / GitHub Pages compatible template engine in pure JavaScript. Prior to 10.25.3, liquidjs 10.25.0 documents root as constraining filenames passed to renderFile() and parseFile(), but top-level file loads do not enforce that boundary. A Liquid instance…
more
configured with an empty temporary directory as root can return the contents of arbitrary files. This vulnerability is fixed in 10.25.3.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.3.2
Mitigating Controls (NIST 800-53 r5) AI
Enforces the intended directory access authorizations that path traversal would otherwise bypass.
Input validation directly neutralizes special path elements before pathname construction occurs.
Least privilege reduces the impact of any unauthorized file access obtained via traversal.
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.
Patching/maintenance can remediate known path-traversal flaws in deployed software (partial prevention of exploitability) but does nothing to stop the coding defect from being introduced in the first place.
PR.AA-05 defines and reviews access policies but does not address code-level pathname neutralization, so neither direction prevents CWE-22.
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.
Security testing in development catches path traversal via static/dynamic analysis.
Secure SDLC mandates input validation and path sanitization that directly prevent path traversal.
Application security requirements include rules for safe file handling and canonicalization.
Secure architecture principles require least-privilege file access and directory isolation.
Secure coding standards explicitly forbid unsafe path construction and mandate safe APIs.
Information access restriction limits which files an application may read or write.