Home/CVE/The email module of Python through 3.11.3 incorrectly parses e-mail addresses that contain a special character. The wron
CVE

CVE-2023-27043

The email module of Python through 3.11.3 incorrectly parses e-mail addresses that contain a special character. The wron

The email module of Python through 3.11.3 incorrectly parses e-mail addresses that contain a special character. The wrong portion of an RFC2822 header is identified as the value of the addr-spec. In some applications, an attacker can bypass a protection mechanism in which application access is granted only after verifying receipt of e-mail to a specific domain (e.g., only @company.example.com addresses may be used for signup).

This occurs in email/_parseaddr.py in recent versions of Python.

MEDIUM · CVSS 5.3 EPSS 0.00161
Schedule remediation
  • Public exploit or PoC is available
  • SSVC automatable: yes - attacks can be scripted at scale
Sigma rules8 YARA rules0

Affected Products & Versions

9
python<= 2.7.18
python>= 3.0 and < 3.8.20
python>= 3.9.0 and < 3.9.20
python>= 3.10.0 and < 3.10.15
python>= 3.11.0 and < 3.11.10

Public Exploits & PoCs

1

Sigma Hunt Rules

8
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
producthighPython Reverse Shell Execution Via PTY And Socket Modules
producthighInline Python Execution - Spawn Shell Via OS System Library
producthighPython One-Liners with Base64 Decoding - Linux
producthighPython Function Execution Security Warning Disabled In Excel
producthighPython One-Liners with Base64 Decoding
producthighPython Spawning Pretty TTY on Windows

Scoring & Timeline

5.3
MEDIUM · CVSS v3.1 · cve@mitre.org
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD19 Apr 2023 · 12:15 AM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
SSVC triage · cisa-vulnrichment
Exploitation
poc
Automatable
yes
Technical impact
partial
SSVC asks the questions that actually drive patch urgency: is it being exploited, can attacks be automated, and how total is the impact.

Vendor Advisories

30
cisa-aa-advisoriesicsa-26-134-16
siemens-csafSSA-577017
siemens-csafSSA-202008
suse-csafopenSUSE-SU-2025:15713-1
🔗

References & Sources

45
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
http://python.orgVendor Advisory
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