CVE-2026-56416: Software Security Vulnerability Vulnerability

MODERATE
Advisory Identifier: GHSA-2845-97v4-7wm3
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CVSS 4.8
CWE-354
Published
Advisory Summary

CVE-2026-56416 is a MODERATE (CVSS 4.8) security vulnerability vulnerability (CWE-354: Improper Validation of Integrity Check Value) affecting Software libraries in the Maven ecosystem. The weakness occurs when the product does not validate or incorrectly validates the integrity check values or "checksums" of a message. this may prevent it from detecting if the data has been modified or corrupted in transmission.. Remediation is available in the latest vendor maintenance releases.

CVE-2026-56416 at a Glance

CVE Identifier CVE-2026-56416
GHSA Identifier GHSA-2845-97v4-7wm3
Severity MODERATE
CVSS v3.1 Base Score 4.8
CWE Classification CWE-354: Improper Validation of Integrity Check Value
Affected Product Software
Package Ecosystem Maven
Published Date
Last Updated

Security Impact

CVSS: 4.8

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:N/I:L/A:L).

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 None (C:N)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2026-56416

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-2026-56416, 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-354: Improper Validation of Integrity Check Value, where the product does not validate or incorrectly validates the integrity check values or "checksums" of a message. this may prevent it from detecting if the data has been modified or corrupted in transmission. 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

In NLnet Labs Unbound up to and including version 1.25.1, when the validator builds the canonical RDATA form for an RRSIG-covered PX/RP/MINFO/SOA RRset, it computes the address of the second embedded domain name as 'datstart + dname_valid(datstart, ...)' and passes it straight to 'query_dname_tolower()' without checking that a second name is actually present in the RDATA. The wire-format parser accepts multi-dname RRs whose RDATA ends after the first name, so an attacker who runs a DNSSEC-signed authoritative server can deliver a record with an absent second domain name (e.g. SOA record) and cause 'query_dname_tolower()' to walk label-by-label through stale bytes in the per-worker 'env->scratch_buffer', past the end of that heap allocation if 'msg-buffer-size' has been lowered from the default. This leads to heap buffer overflow and on a release build the outcome relies heavily on the contents of the buffer tail and the adjacent heap chunk.

References

NVD — CVE-2026-56416 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56416
www.nlnetlabs.nl/downloads/unbound/c... WEB
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-56416.txt

Frequently Asked Questions

What is CVE-2026-56416?
CVE-2026-56416 is a security vulnerability in Software classified as a security vulnerability vulnerability under CWE-354: Improper Validation of Integrity Check Value.
Which Software versions are affected?
Affected versions include releases prior to current release patches.
What version fixes CVE-2026-56416?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
What is the CVSS score of CVE-2026-56416?
CVE-2026-56416 has a CVSS v3.1 base score of 4.8 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L.
What CWE is associated with CVE-2026-56416?
CVE-2026-56416 is classified under CWE-354: Improper Validation of Integrity Check Value (The product does not validate or incorrectly validates the integrity check values or "checksums" of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission.).
How can I check Maven dependencies for CVE-2026-56416?
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-2845-97v4-7wm3",
  "modified" : "2026-07-22T15:31:25Z",
  "published" : "2026-07-22T15:31:25Z",
  "aliases" : [ "CVE-2026-56416" ],
  "details" : "In NLnet Labs Unbound up to and including version 1.25.1, when the validator builds the canonical RDATA form for an RRSIG-covered PX/RP/MINFO/SOA RRset, it computes the address of the second embedded domain name as 'datstart + dname_valid(datstart, ...)' and passes it straight to 'query_dname_tolower()' without checking that a second name is actually present in the RDATA. The wire-format parser accepts multi-dname RRs whose RDATA ends after the first name, so an attacker who runs a DNSSEC-signed authoritative server can deliver a record with an absent second domain name (e.g. SOA record) and cause 'query_dname_tolower()' to walk label-by-label through stale bytes in the per-worker 'env->scratch_buffer', past the end of that heap allocation if 'msg-buffer-size' has been lowered from the default. This leads to heap buffer overflow and on a release build the outcome relies heavily on the contents of the buffer tail and the adjacent heap chunk.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L"
  } ],
  "affected" : [ ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-56416"
  }, {
    "type" : "WEB",
    "url" : "https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-56416.txt"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-354" ],
    "severity" : "MODERATE",
    "github_reviewed" : false,
    "github_reviewed_at" : null,
    "nvd_published_at" : "2026-07-22T14:17:22Z"
  }
}