Medium severity · published Jun 22, 2026
CVE-2026-39904
Gophish 0.12.1 Denial of Service via Office Document Upload
6.5
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 38% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GO
gophish · gophish
through 0.12.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-39904
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-39904
technical-description
https://github.com/ashikmd7/GoPhish-0.12.1/blob/main/Unbounded%20Memory%20Allocation%20in%20Office%20Attachment%20Processing%20Leads%20to%20Server%20DoS/README.md
third-party-advisory
https://www.vulncheck.com/advisories/gophish-denial-of-service-via-office-document-upload
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