CVE-2026-28407: malcontent Nested Archive Extraction Failure Can Vulnerability

MODERATE
Advisory Identifier: GHSA-945p-3jhm-6rcp
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CWE-703
Published
Advisory Summary

CVE-2026-28407 is a MODERATE nested archive extraction failure can vulnerability (CWE-703: Improper Check or Handling of Exceptional Conditions) affecting malcontent libraries in the Go ecosystem. The issue involves nested archive extraction failure can drop content from scan inputs. Remediation is available by upgrading affected packages to version 1.21.0.

CVE-2026-28407 at a Glance

CVE Identifier CVE-2026-28407
GHSA Identifier GHSA-945p-3jhm-6rcp
Severity MODERATE
CVSS v3.1 Base Score N/A
CWE Classification CWE-703: Improper Check or Handling of Exceptional Conditions
Affected Product malcontent
Package Ecosystem Go
Published Date
Last Updated

How to Fix CVE-2026-28407

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

github.com/chainguard-dev/malcontent fixed: 1.21.0 
Upgrade github.com/chainguard-dev/malcontent to 1.21.0
Verify Direct and Transitive Dependencies

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

inspect dependencies for github.com/chainguard-dev/malcontent

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-28407, inspect your project dependencies for malcontent:

inspect dependencies for github.com/chainguard-dev/malcontent

Analyze the terminal output to locate any version of malcontent in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.21.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-703: Improper Check or Handling of Exceptional Conditions, where the product does not properly anticipate or handle exceptional conditions that rarely occur during normal operation of the product. In malcontent, 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

Previously, malcontent would remove nested archives which failed to extract which could potentially leave malicious content. A better approach is to preserve these archives so that malcontent can attempt a best-effort scan of the archive bytes. **Fix**: https://github.com/chainguard-dev/malcontent/pull/1383 **Acknowledgements** malcontent thanks Oleh Konko from [1seal](https://1seal.org/) for discovering and reporting this issue.

CVE-2026-28407 Affected malcontent Versions

1 component(s)
Fixed Versions:
1.21.0
Product / Package Ecosystem Affected Versions Fixed Version
github.com/chainguard-dev/malcontent
golang/github.com/chainguard-dev/malcontent
Go
< 1.21.0
1.21.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/chainguard-dev/malcontent/security/advisories/GHSA-945p-3jhm-6rcp
NVD — CVE-2026-28407 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-28407
malcontent Source Repository REPOSITORY
https://github.com/chainguard-dev/malcontent/pull/1383
Security Fix Commit FIX COMMIT
https://github.com/chainguard-dev/malcontent/commit/356c56659ccfcad0b249a97de8cf71f151ed3ee9
malcontent Source Repository REPOSITORY
https://github.com/chainguard-dev/malcontent

Frequently Asked Questions

What is CVE-2026-28407?
CVE-2026-28407 is a security vulnerability in malcontent involving Nested archive extraction failure can drop content from scan inputs under CWE-703: Improper Check or Handling of Exceptional Conditions.
Which malcontent versions are affected?
Affected versions include releases prior to 1.21.0 across affected packages: github.com/chainguard-dev/malcontent.
What version fixes CVE-2026-28407?
Upgrading to 1.21.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/chainguard-dev/malcontent affected?
Yes, github.com/chainguard-dev/malcontent is affected in releases prior to 1.21.0. Upgrade your dependency to 1.21.0 or later.
What CWE is associated with CVE-2026-28407?
CVE-2026-28407 is classified under CWE-703: Improper Check or Handling of Exceptional Conditions (The product does not properly anticipate or handle exceptional conditions that rarely occur during normal operation of the product.).
How can I check Go dependencies for CVE-2026-28407?
Run the dependency tree command: 'inspect dependencies for github.com/chainguard-dev/malcontent'. 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-945p-3jhm-6rcp",
  "modified" : "2026-02-28T02:50:09Z",
  "published" : "2026-02-28T02:50:09Z",
  "aliases" : [ "CVE-2026-28407" ],
  "summary" : "malcontent: Nested archive extraction failure can drop content from scan inputs",
  "details" : "Previously, malcontent would remove nested archives which failed to extract which could potentially leave malicious content. A better approach is to preserve these archives so that malcontent can attempt a best-effort scan of the archive bytes.\n\n**Fix**:  https://github.com/chainguard-dev/malcontent/pull/1383\n\n**Acknowledgements**\n\nmalcontent thanks Oleh Konko from [1seal](https://1seal.org/) for discovering and reporting this issue.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/chainguard-dev/malcontent"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.21.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/chainguard-dev/malcontent/security/advisories/GHSA-945p-3jhm-6rcp"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-28407"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/chainguard-dev/malcontent/pull/1383"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/chainguard-dev/malcontent/commit/356c56659ccfcad0b249a97de8cf71f151ed3ee9"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/chainguard-dev/malcontent"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-703" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-28T02:50:09Z",
    "nvd_published_at" : "2026-02-27T22:16:23Z"
  }
}