CVE-2026-66486: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-p5w5-qcg3-g8gx
Share
CWE-116
Published
Advisory Summary

CVE-2026-66486 is a MODERATE security vulnerability vulnerability (CWE-116: Improper Encoding or Escaping of Output) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. as a result, the intended structure of the message is not preserved.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-66486 at a Glance

CVE Identifier CVE-2026-66486
GHSA Identifier GHSA-p5w5-qcg3-g8gx
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-116: Improper Encoding or Escaping of Output
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

How to Fix CVE-2026-66486

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-2026-66486, 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-116: Improper Encoding or Escaping of Output, where the product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. as a result, the intended structure of the message is not preserved. 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

GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed. This issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30

References

NVD — CVE-2026-66486 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-66486
cert.pl/en/posts/2026/08/cv... WEB
https://cert.pl/en/posts/2026/08/CVE-2026-66484
git.savannah.gnu.org/cgit/cpio.git WEB
https://git.savannah.gnu.org/cgit/cpio.git

Frequently Asked Questions

What is CVE-2026-66486?
CVE-2026-66486 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-116: Improper Encoding or Escaping of Output.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-66486?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What CWE is associated with CVE-2026-66486?
CVE-2026-66486 is classified under CWE-116: Improper Encoding or Escaping of Output (The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.).
How can I check Maven dependencies for CVE-2026-66486?
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-p5w5-qcg3-g8gx",
  "modified" : "2026-08-10T12:31:50Z",
  "published" : "2026-08-10T12:31:50Z",
  "aliases" : [ "CVE-2026-66486" ],
  "details" : "GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed.\n\n\n\n\nThis issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/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"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-66486"
  }, {
    "type" : "WEB",
    "url" : "https://cert.pl/en/posts/2026/08/CVE-2026-66484"
  }, {
    "type" : "WEB",
    "url" : "https://git.savannah.gnu.org/cgit/cpio.git"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-116" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-10T11:17:27Z"
  }
}