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HIGH

CVE-2021-42771

CVSS v3

7.8

HIGH

EPSS Score

0.8 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • babelPyPIall versions · fixed in 2.9.1
  • babelAlmaLinux:8all versions · fixed in 2.5.1-10.module_el8.6.0+2781+fed64c13and 1 other package
  • python-nose-docsAlmaLinux:8all versions · fixed in 1.3.7-31.module_el8.5.0+2569+5c5719bc
  • python-sqlalchemy-docAlmaLinux:8all versions · fixed in 1.3.2-2.module_el8.5.0+2569+5c5719bc
  • python2-attrsAlmaLinux:8all versions · fixed in 17.4.0-10.module_el8.6.0+2781+fed64c13
  • python2-backportsAlmaLinux:8all versions · fixed in 1.0-16.module_el8.6.0+2781+fed64c13
  • python2-backports-ssl_match_hostnameAlmaLinux:8all versions · fixed in 3.5.0.1-12.module_el8.6.0+2781+fed64c13
  • python2-chardetAlmaLinux:8all versions · fixed in 3.0.4-10.module_el8.6.0+2781+fed64c13

69 more package ranges on OSV.dev

Vendor advisories

  • CVE-2021-42771 Red Hat Product Security711 products fixed · 12 known affected

    python-babel: Relative path traversal allows attacker to load arbitrary locale files and execute arbitrary code

    babel.src as a component of Red Hat Enterprise Linux 6 · python-babel as a component of Red Hat Enterprise Linux 6 · babel.src as a component of Red Hat Enterprise Linux 7

  • RHSA-2021:4201 Red Hat Product Security2 products fixed

    Red Hat Security Advisory: babel security and bug fix update

  • RHSA-2021:4162 Red Hat Product Security239 products fixed

    Red Hat Security Advisory: python38:3.8 and python38-devel:3.8 security update

  • RHSA-2021:4151 Red Hat Product Security264 products fixed

    Red Hat Security Advisory: python27:2.7 security update

  • RHSA-2021:3252 Red Hat Product Security80 products fixed

    Red Hat Security Advisory: python27 security update

  • RHSA-2021:3254 Red Hat Product Security126 products fixed

    Red Hat Security Advisory: rh-python38 security, bug fix, and enhancement update

Full record on NVD

Description

Babel.Locale in Babel before 2.9.1 allows attackers to load arbitrary locale .dat files (containing serialized Python objects) via directory traversal, leading to code execution.

Technical details

Published
2021-10-20

Frequently asked questions

What is CVE-2021-42771?

Babel.Locale in Babel before 2.9.1 allows attackers to load arbitrary locale .dat files (containing serialized Python objects) via directory traversal, leading to code execution.

Is CVE-2021-42771 actively exploited?

Active exploitation of CVE-2021-42771 has not been confirmed. Its EPSS score was 0.8% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-42771?

CVE-2021-42771 has a CVSS v3 base score of 7.8 (HIGH severity).

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