CVE-2026-78381: Software Security Vulnerability Vulnerability

HIGH
Advisory Identifier: GHSA-8f7x-5f58-rfpw
Share
CWE-22
Published
Advisory Summary

CVE-2026-78381 is a HIGH security vulnerability vulnerability (CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-78381 at a Glance

CVE Identifier CVE-2026-78381
GHSA Identifier GHSA-8f7x-5f58-rfpw
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-78381

To remediate this vulnerability, upgrade all affected Software dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

mvn dependency:tree

How to Check if You Are Affected

To determine whether your Java application is affected by CVE-2026-78381, inspect your build dependencies using the Maven Dependency Plugin:

mvn dependency:tree

Analyze the terminal output to locate any version of Software in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than the patched release), your application is affected.

Note: The mvn dependency:tree command inspects the resolved dependency graph declared in your project's POM files; it does not perform automated security scanning or inspect runtime dynamic classpaths. Always verify runtime container classpaths and shaded JARs.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal'), where the product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. In Software, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

RansomLook contains a path traversal vulnerability in the handling of the screen field associated with group posts. The GroupPost.get API handler concatenates the database-controlled screen value directly with the application's source/ directory and opens the resulting path without verifying that the resolved file remains within the intended directory. Because the screen field is free-form and can be populated either through the administrative post editor or through data imported from a remote RansomLook instance, a malicious upstream instance can provide traversal sequences such as ../config/generic.json. When the affected post is subsequently retrieved through the API, RansomLook resolves and reads the attacker-controlled path and returns the contents of the referenced file Base64-encoded in the API response. This can allow an attacker (being admin) controlling imported post data to read arbitrary files accessible to the RansomLook process, potentially exposing sensitive configuration data, API credentials, password hashes, or other application secrets. The attack does not require the malicious upstream to possess an account on the affected RansomLook instance. The vulnerability is addressed by resolving screen paths with os.path.realpath() and verifying that the resolved path remains beneath the application's source/ directory. Validation is performed both when values are written and immediately before files are read. Using canonical paths also prevents traversal through symbolic links that would bypass purely lexical path normalization checks.

References

NVD — CVE-2026-78381 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-78381
Security Fix Commit FIX COMMIT
https://github.com/RansomLook/RansomLook/commit/274faccf65898e88ef54f35f304e0821a852a0b8

Frequently Asked Questions

What is CVE-2026-78381?
CVE-2026-78381 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal').
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-78381?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-78381?
CVE-2026-78381 is classified under CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.).
How can I check Maven dependencies for CVE-2026-78381?
Run the dependency tree command: 'mvn dependency:tree'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8f7x-5f58-rfpw",
  "modified" : "2026-08-24T15:31:53Z",
  "published" : "2026-08-24T15:31:53Z",
  "aliases" : [ "CVE-2026-78381" ],
  "details" : "RansomLook contains a path traversal vulnerability in the handling of the screen field associated with group posts. The GroupPost.get API handler concatenates the database-controlled screen value directly with the application's source/ directory and opens the resulting path without verifying that the resolved file remains within the intended directory.\n\nBecause the screen field is free-form and can be populated either through the administrative post editor or through data imported from a remote RansomLook instance, a malicious upstream instance can provide traversal sequences such as ../config/generic.json. When the affected post is subsequently retrieved through the API, RansomLook resolves and reads the attacker-controlled path and returns the contents of the referenced file Base64-encoded in the API response.\n\nThis can allow an attacker (being admin) controlling imported post data to read arbitrary files accessible to the RansomLook process, potentially exposing sensitive configuration data, API credentials, password hashes, or other application secrets. The attack does not require the malicious upstream to possess an account on the affected RansomLook instance.\n\nThe vulnerability is addressed by resolving screen paths with os.path.realpath() and verifying that the resolved path remains beneath the application's source/ directory. Validation is performed both when values are written and immediately before files are read. Using canonical paths also prevents traversal through symbolic links that would bypass purely lexical path normalization checks.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:N/VA:N/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-78381"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/RansomLook/RansomLook/commit/274faccf65898e88ef54f35f304e0821a852a0b8"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "HIGH",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-24T14:17:05Z"
  }
}