CVE-2026-72860: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-cqgh-7h49-q3mr
CVSS 8.5
CWE-184
Published
Advisory Summary

CVE-2026-72860 is a MODERATE (CVSS 8.5) security vulnerability vulnerability (CWE-184: Incomplete List of Disallowed Inputs) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-72860 at a Glance

CVE Identifier CVE-2026-72860
GHSA Identifier GHSA-cqgh-7h49-q3mr
Severity MODERATE
CVSS v3.1 Base Score 8.5
CWE Classification CWE-184: Incomplete List of Disallowed Inputs
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 8.5

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

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

How to Fix CVE-2026-72860

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-2026-72860, 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-184: Incomplete List of Disallowed Inputs, where the product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete. 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

The POST /api/provider-nodes/validate route in 9router takes a caller-supplied baseUrl and issues server-side HTTP requests to it, guarding the destination with assertPublicUrl from src/shared/utils/ssrfGuard.js. That guard compares hostname strings only: it resolves no DNS, does not revalidate after a redirect, and its IPv4-mapped IPv6 branch is unreachable. The branch matches ^::ffff:(\d+\.\d+\.\d+\.\d+)$, but the WHATWG URL parser canonicalizes such literals to hextets before the guard runs, so new URL("http://[::ffff:127.0.0.1]/").hostname yields [::ffff:7f00:1] and the pattern is tested against a string it is never handed. Every IPv4-mapped address therefore passes, and http://[::ffff:7f00:1] and http://[::ffff:a9fe:a9fe] reach loopback and link-local metadata addresses; a hostname whose A record points at an internal address passes as well because no resolution occurs. In the custom-embedding branch the upstream response body is truncated to 200 bytes and returned to the caller whenever the upstream status is neither 2xx nor 401 nor 403, which discloses the beginning of internal responses, and the other validation types remain usable for blind internal port scanning through status and timing differences. The caller-supplied apiKey is forwarded to the internal destination as an Authorization Bearer header. A dashboard session is required by default, and none is required when requireLogin is disabled.

References

Frequently Asked Questions

What is CVE-2026-72860?
CVE-2026-72860 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-184: Incomplete List of Disallowed Inputs.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-72860?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-72860?
CVE-2026-72860 has a CVSS v3.1 base score of 8.5 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N.
What CWE is associated with CVE-2026-72860?
CVE-2026-72860 is classified under CWE-184: Incomplete List of Disallowed Inputs (The product implements a protection mechanism that relies on a list of inputs (or properties of inputs) that are not allowed by policy or otherwise require other action to neutralize before additional processing takes place, but the list is incomplete.).
How can I check Maven dependencies for CVE-2026-72860?
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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cqgh-7h49-q3mr",
  "modified" : "2026-08-21T00:31:23Z",
  "published" : "2026-08-21T00:31:23Z",
  "aliases" : [ "CVE-2026-72860" ],
  "details" : "The POST /api/provider-nodes/validate route in 9router takes a caller-supplied baseUrl and issues server-side HTTP requests to it, guarding the destination with assertPublicUrl from src/shared/utils/ssrfGuard.js. That guard compares hostname strings only: it resolves no DNS, does not revalidate after a redirect, and its IPv4-mapped IPv6 branch is unreachable. The branch matches ^::ffff:(\\d+\\.\\d+\\.\\d+\\.\\d+)$, but the WHATWG URL parser canonicalizes such literals to hextets before the guard runs, so new URL(\"http://[::ffff:127.0.0.1]/\").hostname yields [::ffff:7f00:1] and the pattern is tested against a string it is never handed. Every IPv4-mapped address therefore passes, and http://[::ffff:7f00:1] and http://[::ffff:a9fe:a9fe] reach loopback and link-local metadata addresses; a hostname whose A record points at an internal address passes as well because no resolution occurs. In the custom-embedding branch the upstream response body is truncated to 200 bytes and returned to the caller whenever the upstream status is neither 2xx nor 401 nor 403, which discloses the beginning of internal responses, and the other validation types remain usable for blind internal port scanning through status and timing differences. The caller-supplied apiKey is forwarded to the internal destination as an Authorization Bearer header. A dashboard session is required by default, and none is required when requireLogin is disabled.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/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-2026-72860"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/decolua/9router/issues/3293"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/decolua/9router/pull/3370"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/decolua/9router"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/decolua/9router/blob/master/src/app/api/provider-nodes/validate/route.js"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/decolua/9router/blob/master/src/shared/utils/ssrfGuard.js"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/9router-server-side-request-forgery-via-api-provider-nodes-validate-because-the-ipv4-mapped-ipv6-denylist-check-is-unreachable"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-184" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-08-20T22:18:05Z"
  }
}