Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2020-15523

CVE-2020-15523HIGH

n/a n/a — In Python 3.6 through 3.6.10, 3.7 through 3.7.8, 3.8 through 3.8.4rc1, and 3.9 through 3.9.0b4 on Windows, a Trojan horse python3.dll mig…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   L   N   R  U  H  H  H    7.8   .0095   60.4     —

AFFECTED
  Product  Versions  Fixed
  n/a      n/a –     —

TIMELINE
  Jul 4   Reserved by mitre
  Jul 4   Published (CNA: mitre)
  Oct 8   ENRICHED — CVE-2020-15523. Received CVSS 7.8 and CPE data from NVD.

CWE-427, CWE-908 · CNA: mitre · CVSS v3.1 · 4 references · NVD status: Modified

Description

In Python 3.6 through 3.6.10, 3.7 through 3.7.8, 3.8 through 3.8.4rc1, and 3.9 through 3.9.0b4 on Windows, a Trojan horse python3.dll might be used in cases where CPython is embedded in a native application. This occurs because python3X.dll may use an invalid search path for python3.dll loading (after Py_SetPath has been used). NOTE: this issue CANNOT occur when using python.exe from a standard (non-embedded) Python installation on Windows.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
July 4, 2020	Reserved	Reserved by mitre
July 4, 2020	Published	Published (CNA: mitre)
October 8, 2026	ENRICHED	ENRICHED — CVE-2020-15523. Received CVSS 7.8 and CPE data from NVD.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	n/a	—	n/a	—

Weaknesses

CWE-427 · CWE-908

References (4)

https://bugs.python.org/issue29778 [Issue Tracking, Patch, Vendor Advisory]
https://cert-portal.siemens.com/productcert/html/ssa-398330.html
https://github.com/python/cpython/pull/21297 [Patch, Third Party Advisory]
https://security.netapp.com/advisory/ntap-20210312-0004/ [Issue Tracking, Patch, Third Party Advisory]

Authoritative record: CVE-2020-15523 at cve.org

Weaknesses: CWE-427 · CWE-908

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-15523 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.