CVE-2025-59937Public exploitNetwork attack vector

Email misrouting via unescaped SMTP envelope addresses

Published Sep 29, 2025 · Updated Sep 29, 2025

Argument injection in Winni Neessen go-mail before 0.7.1 allows remote attackers to misroute email via crafted sender or recipient addresses. The sender and recipient accessors passed raw mail.Address.Address values into SMTP MAIL FROM and RCPT TO commands instead of escaped String() output. Exploitation requires an embedding application to accept attacker-controlled mail addresses; crafted quoted local parts can alter routing or smuggle ESMTP parameters.

CVSS severity8.2
High
EPSS probability0.54%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Argument injection in Winni Neessen go-mail before 0.7.1 allows remote attackers to misroute email via crafted sender or recipient addresses. The sender and recipient accessors passed raw mail.Address.Address values into SMTP MAIL FROM and RCPT TO commands instead of escaped String() output. Exploitation requires an embedding application to accept attacker-controlled mail addresses; crafted quoted local parts can alter routing or smuggle ESMTP parameters.

The record

CVE
CVE-2025-59937
Published
Sep 29, 2025
Updated
Sep 29, 2025
Vendor
Winni Neessen
Product
go-mail
Classifications
CWE-88
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 29, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 29, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.7.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Winni Neessen · go-mailversion=< 0.7.1

Published CVSS scores

8.2GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-88Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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