High

Improper Input Validation in pip

  • Disclosed: 10.11.2021
  • Updated: 11.10.2026 12:19

A flaw was found in python-pip in the way it handled Unicode separators in git references. A remote attacker could possibly use this issue to install a different revision on a repository. The highest threat from this vulnerability is to data integrity. This is fixed in python-pip version 21.1.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Python (PyPI) pip < 21.1 21.1

References

CVSS score 5.7/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:H/A:N
Weakness (CWE)
CWE-20
Platform
Python (PyPI)
Package
pip
Disclosed
10.11.2021
Updated
11.10.2026 12:19

Sources and licenses

OSV / GitHub Advisory Database - PYSEC-2021-437 - PyPA Advisory Database; CC BY 4.0

OSV / GitHub Advisory Database - GHSA-5xp3-jfq3-5q8x - CC BY 4.0

Vulnerability history: pip

All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (13) in the archive
Total entries
13
First → latest
08.2013 07.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 4
  • Medium 8
  • Low 1

Disclosures per year

  1. 2017: 0
  2. 2018: 0
  3. 2019: 1
  4. 2020: 1
  5. 2021: 1
  6. 2022: 0
  7. 2023: 1
  8. 2024: 0
  9. 2025: 1
  10. 2026: 5

earlier: 3

Severity:
  1. Improper Input Validation in pip this entry
    High · 5.7 CVE-2021-3572 < 21.1 21.1
  2. High · 7.5 CVE-2019-20916 < 19.2 19.2
  3. High · 5.9 CVE-2013-5123 < 1.5 1.5
  4. High · 8.4 CVE-2013-1629 < 1.3 1.3

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