What’s Vulnerable › Vulnerabilities

CVE-2025-15366: IMAP command injection in user-controlled commands

• Severity: medium (CVSS 5.9 v4.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-01-20 · updated 2026-08-06
• Weakness: CWE-77

Description

The imaplib module, when passed a user-controlled command, can have additional commands injected using newlines. Mitigation rejects commands containing control characters.

Affected products

• Python: before 3.13.15; from 3.14.0 before 3.14.7; from 3.15.0a1 before 3.15.0a6 — fixed in 3.13.15, 3.14.7, 3.15.0a6

How to fix

Upgrade to a fixed version: Python 3.13.15, 3.14.7, 3.15.0a6. Check the vendor advisory for mitigations.

References

• https://github.com/python/cpython/commit/298182272a740ce2016aee2f54acbd0bba1944c1
• https://github.com/python/cpython/commit/6262704b134db2a4ba12e85ecfbd968534f28b45
• https://github.com/python/cpython/commit/71926d943c05bde79bd2a866933103541d91b6a2
• https://github.com/python/cpython/commit/d0921efb665aff26b378f495e5ff84f7e3fe649d
• https://github.com/python/cpython/commit/f2cd7ef89aa8a0dcbc7283bbd39548b76f2a736a
• https://github.com/python/cpython/issues/143921
• https://github.com/python/cpython/pull/143922
• https://mail.python.org/archives/list/security-announce@python.org/thread/DD7C7JZJYTBXMDOWKCEIEBJLBRU64OMR/

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