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-2019-9636

CVE-2019-9636CRITICAL

n/a n/a — Python 2.7.x through 2.7.16 and 3.x through 3.7.2 is affected by: Improper Handling of Unicode Encoding (with an incorrect netloc) during…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  H  H  H    9.8   .0881   95.1     —

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

TIMELINE
  Mar 8   Reserved by mitre
  Mar 8   Published (CNA: mitre)
  Oct 7   RESCORED — CVE-2019-9636. CVSS 5.3 → 9.8 (NVD).

CWE-173 · CNA: mitre · CVSS v3.1 · 52 references · NVD status: Modified

Description

Python 2.7.x through 2.7.16 and 3.x through 3.7.2 is affected by: Improper Handling of Unicode Encoding (with an incorrect netloc) during NFKC normalization. The impact is: Information disclosure (credentials, cookies, etc. that are cached against a given hostname). The components are: urllib.parse.urlsplit, urllib.parse.urlparse. The attack vector is: A specially crafted URL could be incorrectly parsed to locate cookies or authentication data and send that information to a different host than when parsed correctly. This is fixed in: v2.7.17, v2.7.17rc1, v2.7.18, v2.7.18rc1; v3.5.10, v3.5.10rc1, v3.5.7, v3.5.8, v3.5.8rc1, v3.5.8rc2, v3.5.9; v3.6.10, v3.6.10rc1, v3.6.11, v3.6.11rc1, v3.6.12, v3.6.9, v3.6.9rc1; v3.7.3, v3.7.3rc1, v3.7.4, v3.7.4rc1, v3.7.4rc2, v3.7.5, v3.7.5rc1, v3.7.6, v3.7.6rc1, v3.7.7, v3.7.7rc1, v3.7.8, v3.7.8rc1, v3.7.9.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
March 8, 2019	Reserved	Reserved by mitre
March 8, 2019	Published	Published (CNA: mitre)
October 7, 2026	RESCORED	RESCORED — CVE-2019-9636. CVSS 5.3 → 9.8 (NVD).

Affected

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

Weaknesses

CWE-173

References (52)

http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00092.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00097.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00024.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00050.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00042.html [Mailing List, Third Party Advisory]
http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html [Mailing List, Third Party Advisory]
http://www.securityfocus.com/bid/107400 [Third Party Advisory, VDB Entry]
https://access.redhat.com/errata/RHBA-2019:0763 [Third Party Advisory]
https://access.redhat.com/errata/RHBA-2019:0764 [Third Party Advisory]
https://access.redhat.com/errata/RHBA-2019:0959 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:0710 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:0765 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:0806 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:0902 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:0981 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:0997 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:1467 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:2980 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:3170 [Third Party Advisory]
https://bugs.python.org/issue36216 [Issue Tracking, Patch, Vendor Advisory]
https://github.com/python/cpython/pull/12201 [Patch, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2019/06/msg00022.html [Mailing List, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2019/06/msg00023.html [Mailing List, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2020/07/msg00011.html [Mailing List, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2020/08/msg00034.html [Mailing List, Third Party Advisory]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2ORNTF62QPLMJXIQ7KTZQ2776LMIXEKL/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/44TS66GJMO5H3RLMVZEBGEFTB6O2LJJU/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/46PVWY5LFP4BRPG3BVQ5QEEFYBVEXHCK/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4X3HW5JRZ7GCPSR7UHJOLD7AWLTQCDVR/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AEZ5IQT7OF7Q2NCGIVABOWYGKO7YU3NJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CFBAAGM27H73OLYBUA2IAZFSUN6KGLME/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/D3LXPABKVLFYUHRYJPM3CSS5MS6FXKS7/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/E2HP37NUVLQSBW3J735A2DQDOZ4ZGBLY/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ER6LONC2B2WYIO56GBQUDU6QTWZDPUNQ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HQEQLXLOCR3SNM3AA5RRYJFQ5AZBYJ4L/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ICBEGRHIPHWPG2VGYS6R4EVKVUUF4AQW/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IFAXBEY2TGOBDRKTR556JBXBVFSAKD6I/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JCPGLTTOBB3QEARDX4JOYURP6ELNNA2V/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JMWSKTNOHSUOT3L25QFJAVCFYZX46FYK/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JSKPGPZQNTAULHW4UH63KGOOUIDE4RRB/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JXASHCDD4PQFKTMKQN4YOP5ZH366ABN4/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/KRYFIMISZ47NTAU3XWZUOFB7CYL62KES/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L25RTMKCF62DLC2XVSNXGX7C7HXISLVM/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M34WOYCDKTDE5KLUACE2YIEH7D37KHRX/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TR6GCO3WTV4D5L23WTCBF275VE6BVNI3/
https://python-security.readthedocs.io/vuln/urlsplit-nfkc-normalization.html [Patch, Third Party Advisory]
https://security.gentoo.org/glsa/202003-26 [Third Party Advisory]
https://security.netapp.com/advisory/ntap-20190517-0001/ [Third Party Advisory]
https://usn.ubuntu.com/4127-1/ [Third Party Advisory]
https://usn.ubuntu.com/4127-2/ [Third Party Advisory]
https://www.oracle.com/security-alerts/cpujan2020.html [Third Party Advisory]
https://www.oracle.com/security-alerts/cpujul2022.html

Authoritative record: CVE-2019-9636 at cve.org

Weaknesses: CWE-173

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2019-9636 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.