CVE-2026-61815Public exploitNetwork attack vectorHinoki check available

Message exfiltration via attachment filename header injection

Published Sep 24, 2026 · Updated Sep 24, 2026

CRLF injection in ZBateson MailMimeParser before 3.0.6 and 4.0.0 through 4.0.1 allows remote attackers to forge MIME headers. MultipartHelper::createAndAddPartForAttachment passes transliterated filenames to MimePart::setRawHeader without removing CR or LF, while decoding paths can restore those bytes. Exploitation requires an application to build or forward mail with an attacker-influenced filename; an injected Bcc header can disclose the outgoing message.

CVSS severity7.2
High
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

CRLF injection in ZBateson MailMimeParser before 3.0.6 and 4.0.0 through 4.0.1 allows remote attackers to forge MIME headers. MultipartHelper::createAndAddPartForAttachment passes transliterated filenames to MimePart::setRawHeader without removing CR or LF, while decoding paths can restore those bytes. Exploitation requires an application to build or forward mail with an attacker-influenced filename; an injected Bcc header can disclose the outgoing message.

The record

CVE
CVE-2026-61815
Published
Sep 24, 2026
Updated
Sep 24, 2026
Vendor
ZBateson
Product
MailMimeParser
Classifications
CWE-93, CAPEC-15
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 24, 2026Record 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=< 3.0.6
  2. Affected versionversion=>= 4.0.0, < 4.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ZBateson · MailMimeParserversion=< 3.0.6; version=>= 4.0.0, < 4.0.2

Published CVSS scores

7.2GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/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.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-93Improper Neutralization of CRLF Sequences ('CRLF Injection')
CAPEC-15Command Delimiters

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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