Reference page — cumulative record through Thursday, October 8, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2020-8492

CVE-2020-8492MEDIUM

n/a n/a — Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to condu…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   R  U  N  N  H    6.5   .0662   93.7     —

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

TIMELINE
  Jan 30  Reserved by mitre
  Jan 30  Published (CNA: mitre)
  Oct 7   EXPLOIT PUBLISHED — CVE-2020-8492. Public exploit reference added.

CWE-400 · CNA: mitre · CVSS v3.1 · 16 references · NVD status: Modified

Description

Python 2.7 through 2.7.17, 3.5 through 3.5.9, 3.6 through 3.6.10, 3.7 through 3.7.6, and 3.8 through 3.8.1 allows an HTTP server to conduct Regular Expression Denial of Service (ReDoS) attacks against a client because of urllib.request.AbstractBasicAuthHandler catastrophic backtracking.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
January 30, 2020	Reserved	Reserved by mitre
January 30, 2020	Published	Published (CNA: mitre)
October 7, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2020-8492. Public exploit reference added.

Affected

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

Weaknesses

CWE-400

References (16)

http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00003.html [Third Party Advisory]
https://bugs.python.org/issue39503 [Issue Tracking, Vendor Advisory]
https://github.com/python/cpython/pull/18284 [Patch, Third Party Advisory]
https://lists.apache.org/thread.html/rdb31a608dd6758c6093fd645aea3fbf022dd25b37109b6aaea5bc0b5%40%3Ccommits.cassandra.apache.org%3E
https://lists.apache.org/thread.html/rfec113c733162b39633fd86a2d0f34bf42ac35f711b3ec1835c774da%40%3Ccommits.cassandra.apache.org%3E
https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html [Mailing List, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2023/05/msg00024.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/7WOKDEXLYW5UQ4S7PA7E37IITOC7C56J/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/A5NSAX4SC3V64PGZUPH7PRDLSON34Q5A/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/APGWEMYZIY5VHLCSZ3HD67PA5Z2UQFGH/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UESGYI5XDAHJBATEZN3MHNDUBDH47AS6/
https://python-security.readthedocs.io/vuln/urllib-basic-auth-regex.html [Exploit, Third Party Advisory]
https://security.gentoo.org/glsa/202005-09 [Third Party Advisory]
https://security.netapp.com/advisory/ntap-20200221-0001/ [Third Party Advisory]
https://usn.ubuntu.com/4333-1/ [Third Party Advisory]
https://usn.ubuntu.com/4333-2/ [Third Party Advisory]

Authoritative record: CVE-2020-8492 at cve.org

Weaknesses: CWE-400

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2020-8492 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 Thursday, October 8, 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.