CVE-2026-39904: Github.com/gophish/gophish Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-42jc-v69j-g38f
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CVSS 6.5
CWE-770
Published
Advisory Summary

CVE-2026-39904 is a HIGH (CVSS 6.5) denial of service vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Github.com/gophish/gophish libraries in the Go ecosystem. The issue involves gophish contains a denial of service vulnerability. Remediation is available in the latest vendor maintenance releases.

CVE-2026-39904 at a Glance

CVE Identifier CVE-2026-39904
GHSA Identifier GHSA-42jc-v69j-g38f
Severity HIGH
CVSS v3.1 Base Score 6.5
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Github.com/gophish/gophish
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.5

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:U/C:N/I:N/A:H).

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

How to Fix CVE-2026-39904

To remediate this vulnerability, upgrade all affected Github.com/gophish/gophish 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/gophish/gophish fixed: Latest secure release 
Upgrade github.com/gophish/gophish to Latest secure release
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/gophish/gophish

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-39904, inspect your project dependencies for Github.com/gophish/gophish:

inspect dependencies for github.com/gophish/gophish

Analyze the terminal output to locate any version of Github.com/gophish/gophish 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: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Github.com/gophish/gophish, 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

Gophish through 0.12.1 contains a denial of service vulnerability that allows authenticated users with the User role to exhaust server memory by uploading a crafted Office document as an email template attachment. The ApplyTemplate() function in models/attachment.go processes Office documents as ZIP archives and calls ioutil.ReadAll() on each contained file entry without enforcing size restrictions on uncompressed content, allowing a zip bomb payload to expand to several gigabytes in memory and cause the process to be terminated by the operating system.

CVE-2026-39904 Affected Github.com/gophish/gophish Versions

1 component(s)
Product / Package Ecosystem Affected Versions Fixed Version
github.com/gophish/gophish
golang/github.com/gophish/gophish
Go
≤ 0.12.1

References

NVD — CVE-2026-39904 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39904
Github.com/gophish/gophish Source Repository REPOSITORY
https://github.com/ashikmd7/GoPhish-0.12.1/blob/main/Unbounded%20Memory%20Allocation%20in%20Office%20Attachment%20Processing%20Leads%20to%20Server%20DoS/README.md
Github.com/gophish/gophish Source Repository REPOSITORY
https://github.com/gophish/gophish
www.vulncheck.com/advisories/gophish-... WEB
https://www.vulncheck.com/advisories/gophish-denial-of-service-via-office-document-upload

Frequently Asked Questions

What is CVE-2026-39904?
CVE-2026-39904 is a security vulnerability in Github.com/gophish/gophish involving Gophish contains a denial of service vulnerability under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Github.com/gophish/gophish versions are affected?
Affected versions include releases prior to current release patches across affected packages: github.com/gophish/gophish.
What version fixes CVE-2026-39904?
Upgrading to current release patches (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/gophish/gophish affected?
Yes, github.com/gophish/gophish is affected in releases prior to Latest secure release. Upgrade your dependency to Latest secure release or later.
What is the CVSS score of CVE-2026-39904?
CVE-2026-39904 has a CVSS v3.1 base score of 6.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-39904?
CVE-2026-39904 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check Go dependencies for CVE-2026-39904?
Run the dependency tree command: 'inspect dependencies for github.com/gophish/gophish'. 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-42jc-v69j-g38f",
  "modified" : "2026-08-06T19:16:24Z",
  "published" : "2026-06-22T21:31:00Z",
  "aliases" : [ "CVE-2026-39904" ],
  "summary" : "Gophish contains a denial of service vulnerability",
  "details" : "Gophish through 0.12.1 contains a denial of service vulnerability that allows authenticated users with the User role to exhaust server memory by uploading a crafted Office document as an email template attachment. The ApplyTemplate() function in models/attachment.go processes Office documents as ZIP archives and calls ioutil.ReadAll() on each contained file entry without enforcing size restrictions on uncompressed content, allowing a zip bomb payload to expand to several gigabytes in memory and cause the process to be terminated by the operating system.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/gophish/gophish"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "0.12.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-39904"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/ashikmd7/GoPhish-0.12.1/blob/main/Unbounded%20Memory%20Allocation%20in%20Office%20Attachment%20Processing%20Leads%20to%20Server%20DoS/README.md"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/gophish/gophish"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/gophish-denial-of-service-via-office-document-upload"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-06T19:16:24Z",
    "nvd_published_at" : "2026-06-22T21:16:23Z"
  }
}