CVE-2025-15367
cpython: POP3 command injection in user-controlled commands
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · January 21, 2026
Updated · May 12, 2026
Description
A flaw was found in the poplib module in the Python standard library. The poplib module does not reject control characters, such as newlines, in user-controlled input passed to POP3 commands. This issue allows an attacker to inject additional commands to be executed in the POP3 server.
Statement
To exploit this issue, an attacker needs to have the privileges required to send malicious input to an application that sends POP3 commands to a server. Additionally, this flaw can allow attackers to manipulate the state of the mailbox (e.g., delete emails) and to potentially read metadata or specific email content, but it does not allow arbitrary code execution or OS command injection. Due to these reasons, this issue has been rated with a moderate severity.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
To mitigate this vulnerability, ensure that no data passed to the poplib module contains newline or carriage return characters.
CVSS / CWE
CVSS 3.1 · 7.1CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:N
CWE-77 · Improper Neutralization of Special Elements used in a Command ('Command Injection')