CVE-2026-82973
Received Received - Intake

Improper CRLF Injection in Docker-Mailbox IMAP Command

Publication date: 2026-09-29

Last updated on: 2026-09-29

Assigner: GitLab Inc.

Description
Improper neutralization of CRLF sequences in IMAP command construction in psyb0t/docker-mailbox before 0.4.13 allows a remote unauthenticated attacker, when bearer-token authentication is not configured, to inject additional IMAP commands into an authenticated upstream mailbox connection via crafted folder, UID, or search values.

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Meta Information

Published
2026-09-29
Last Modified
2026-09-29
Generated
2026-09-29
AI Q&A
2026-09-29
EPSS Evaluated
N/A
NVD
CVE-2026-82973
EUVD
EUVD-2026-88759

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
psyb0t docker-mailbox 0.4.13
psyb0t docker-mailbox to 0.4.13 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-93 The product uses CRLF (carriage return line feeds) as a special element, e.g. to separate lines or records, but it does not neutralize or incorrectly neutralizes CRLF sequences from inputs.

Attack-Flow Graph

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Executive Summary

This is an IMAP command injection vulnerability in psyb0t/docker-mailbox before version 0.4.13. It occurs due to improper neutralization of CRLF sequences in IMAP command construction. When bearer-token authentication is not enabled, a remote unauthenticated attacker can inject additional IMAP commands into an authenticated upstream mailbox connection by crafting malicious folder, UID, or search values. The attacker uses URL-encoded CR/LF characters (%0D%0A) to terminate the current command and append malicious commands like STORE +FLAGS (\Deleted) followed by EXPUNGE, which can delete entire folders through read-only routes.

Detection Guidance

To detect this vulnerability, monitor IMAP server logs for unusual commands or patterns. Check for CR/LF sequences (%0D%0A) in folder, UID, or search parameters. Use network traffic analysis tools like tcpdump or Wireshark to inspect IMAP traffic for injected commands such as STORE +FLAGS or EXPUNGE.

Impact Analysis

This vulnerability allows remote attackers to delete folders and emails through read-only routes without authentication. If exploited, it could lead to data loss, unauthorized modifications to mailbox contents, and potential disruption of email services. The high CVSS score (9.4) indicates severe impact on confidentiality, integrity, and availability of the affected system.

Compliance Impact

This vulnerability could lead to unauthorized data deletion or modification, violating integrity and availability requirements under GDPR and HIPAA. GDPR requires protection against unauthorized data loss or alteration, while HIPAA mandates integrity controls for protected health information. Exploitation could result in non-compliance, potential fines, and reputational damage due to compromised data integrity.

Mitigation Strategies

Upgrade to psyb0t/docker-mailbox version 0.4.13 or later. Implement strict input validation for IMAP parameters to reject CR, LF, and NUL characters. Ensure UIDs contain only digits and sequence-set punctuation. Escape folder names to prevent command injection.

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