CVE-2026-100837: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-frqc-cxqj-qxmv
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CVSS 3.7
CWE-1289
Published
Advisory Summary

CVE-2026-100837 is a MODERATE (CVSS 3.7) security vulnerability vulnerability (CWE-1289: Improper Validation of Unsafe Equivalence in Input) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-100837 at a Glance

CVE Identifier CVE-2026-100837
GHSA Identifier GHSA-frqc-cxqj-qxmv
Severity MODERATE
CVSS v3.1 Base Score 3.7
CWE Classification CWE-1289: Improper Validation of Unsafe Equivalence in Input
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 3.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2026-100837

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-2026-100837, 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 & RFC 5280 Specification

Under RFC 5280 specifications for X.509 certificates, the Name Constraints extension defines a namespace within which all subsequent subject names in a certification path must be located. Constraints apply to various name forms including directory names, IP addresses, rfc822Name (email addresses), and uniformResourceIdentifier (URI) entries. Specifically, during certificate path validation, affected versions of Software failed to properly normalize or enforce boundary checks when domain names contained trailing dot (.) characters. Because domain names with a trailing dot signify fully qualified domain names (FQDNs), this omission allowed non-conforming certificates to be improperly validated as compliant with the defined name constraints.

Source Advisory Statement

Contrast (Edgeless Systems) through 1.20.0 performs unanchored suffix matching when selecting per-registry configuration in the imagepuller. Config.registryFor strips a single trailing dot and then uses strings.HasSuffix(hostname, fqdn) without requiring a DNS label boundary, so a registry entry such as [registries."ghcr.io."] is also applied to any host whose name merely ends in that byte sequence, including attacker-registered domains such as evilghcr.io. When an image or layer is pulled from such a sibling domain, the imagepuller sends the configured Authorization header (basic auth, registry token, or identity token), trusts the configured custom CA bundle, follows the configured mirror, and honours insecure-skip-verify (disabling TLS verification) for that host. Image integrity is not affected, as image bytes remain pinned by digest in the policy and are validated after the pull. Configurations that use a leading dot (e.g., [registries.".example.registry"]) are unaffected.

References

GitHub Advisory / Wiki ADVISORY
https://github.com/edgelesssys/contrast/security/advisories/GHSA-6c87-g9pw-78fx
NVD — CVE-2026-100837 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-100837
www.vulncheck.com/advisories/edgeless... WEB
https://www.vulncheck.com/advisories/edgeless-systems-contrast-through-1.20.0-credential-leak-via-registry-suffix-matching

Frequently Asked Questions

What is CVE-2026-100837?
CVE-2026-100837 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-1289: Improper Validation of Unsafe Equivalence in Input.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-100837?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-100837?
CVE-2026-100837 has a CVSS v3.1 base score of 3.7 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2026-100837?
CVE-2026-100837 is classified under CWE-1289: Improper Validation of Unsafe Equivalence in Input (The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.).
How can I check Maven dependencies for CVE-2026-100837?
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-frqc-cxqj-qxmv",
  "modified" : "2026-09-27T03:31:04Z",
  "published" : "2026-09-27T03:31:04Z",
  "aliases" : [ "CVE-2026-100837" ],
  "details" : "Contrast (Edgeless Systems) through 1.20.0 performs unanchored suffix matching when selecting per-registry configuration in the imagepuller. Config.registryFor strips a single trailing dot and then uses strings.HasSuffix(hostname, fqdn) without requiring a DNS label boundary, so a registry entry such as [registries.\"ghcr.io.\"] is also applied to any host whose name merely ends in that byte sequence, including attacker-registered domains such as evilghcr.io. When an image or layer is pulled from such a sibling domain, the imagepuller sends the configured Authorization header (basic auth, registry token, or identity token), trusts the configured custom CA bundle, follows the configured mirror, and honours insecure-skip-verify (disabling TLS verification) for that host. Image integrity is not affected, as image bytes remain pinned by digest in the policy and are validated after the pull. Configurations that use a leading dot (e.g., [registries.\".example.registry\"]) are unaffected.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/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:X"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/edgelesssys/contrast/security/advisories/GHSA-6c87-g9pw-78fx"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-100837"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/edgeless-systems-contrast-through-1.20.0-credential-leak-via-registry-suffix-matching"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1289" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-09-27T02:17:21Z"
  }
}