CVE-2021-42771

HIGHNVD 7.87.8—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.8 under NVD CVSS v3. EPSS exploit probability: 0.7%, top 50% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this week
7.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 7.8Exploit: NoneExposed: 0

A fix is available — apply it.

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.

CVSS v3
7.8
EG Score
7.8(medium)
EG Risk
—
EPSS
49.9%
KEV
Not listed

Published

October 20, 2021

Last Modified

November 21, 2024

References (10)

Vendor Advisories for CVE-2021-42771(3)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatpython27:2.7-8050020210811095446.3e7ace8b2021-11-09redhat
redhatpython38-devel:3.8-8050020210811101222.e3d35cca2021-11-09redhat
redhatbabel-0:2.5.1-7.el82021-11-09redhat
redhatpython27-python-pygments-0:1.5-5.el72021-08-24redhat
redhatrh-python38-python-urllib3-0:1.25.7-7.el72021-08-24redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
PyPI(1)
PackageVulnerable rangeFixed inDependents
babel0.8 ... 2.9.0 (31 versions)2.9.1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(3)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 12× in last 7d / 50× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 107 total refreshes for this CVE.

  1. 2026-07-22 22:51 UTCEG score recompute
  2. 2026-07-22 14:06 UTCEPSS rescore
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Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2021-42771?
CVE-2021-42771 is a high vulnerability published on October 20, 2021. 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.
When was CVE-2021-42771 disclosed?
CVE-2021-42771 was first published in the National Vulnerability Database on October 20, 2021, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2021-42771 actively exploited?
CVE-2021-42771 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 49.9% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2021-42771?
CVE-2021-42771 has a CVSS v3 base score of 7.8 (NVD).
How do I remediate CVE-2021-42771?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2021-42771, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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