CVE-2025-15366Network attack vectorHinoki check available

Mailbox manipulation via newline-injected IMAP commands

Published Jan 20, 2026 · Updated Jan 20, 2026

Command injection in CPython imaplib allows remote authenticated users to alter mailbox state through crafted IMAP arguments. imaplib command construction accepts embedded carriage returns or line feeds in caller-supplied arguments, allowing the terminator to start an additional command on the IMAP server. The application must pass attacker-controlled values into an IMAP command; exploitation can delete, move, or flag messages or read metadata or message content, but does not execute operating-system commands.

CVSS severity5.9
Medium
EPSS probability0.38%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Command injection in CPython imaplib allows remote authenticated users to alter mailbox state through crafted IMAP arguments. imaplib command construction accepts embedded carriage returns or line feeds in caller-supplied arguments, allowing the terminator to start an additional command on the IMAP server. The application must pass attacker-controlled values into an IMAP command; exploitation can delete, move, or flag messages or read metadata or message content, but does not execute operating-system commands.

The record

CVE
CVE-2025-15366
Published
Jan 20, 2026
Updated
Jan 20, 2026
Vendor
Python Software Foundation
Product
CPython
Classifications
CWE-77
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 20, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 20, 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=0 <3.15.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Python Software Foundation · CPythonversion=0 <3.15.0

Published CVSS scores

5.9Python Software FoundationCVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA: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.

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

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-77Improper Neutralization of Special Elements used in a Command ('Command Injection')

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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