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CVE-2019-9636

critical

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.

Vendor / product: Python — python

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.

CVSS
9.8
9.8 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2019-03-08 21:29
Modified: 2026-10-14 07:16
NVD status: Modified
Last synced 1 day ago
Verified against the source API 2026-10-27 07:06 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

python / python ≥2.7.0 <2.7.17, ≥3.0.0 <3.4.10, ≥3.5.0 <3.5.7, ≥3.6.0 <3.6.9, ≥3.7.0 <3.7.3
fedoraproject / fedora 28, 29, 30, 31
opensuse / leap 15.0, 15.1, 42.3
debian / debian_linux 8.0, 9.0
canonical / ubuntu_linux 12.04, 14.04, 16.04, 18.04, 19.04
redhat / openshift_container_platform 3.11
redhat / enterprise_linux 7.5, 8.0
redhat / enterprise_linux_desktop 6.0
redhat / enterprise_linux_eus 7.5, 8.1, 8.2, 8.4, 8.6
redhat / enterprise_linux_server 6.0
redhat / enterprise_linux_server_aus 7.4, 8.2, 8.4
redhat / enterprise_linux_server_eus 5.6
redhat / enterprise_linux_server_tus 7.4, 8.2, 8.4, 8.6
redhat / enterprise_linux_workstation 6.0
redhat / virtualization 4.0
oracle / sun_zfs_storage_appliance_kit 8.8.6

Weakness classification (CWE)

NVD-CWE-noinfo CWE-173

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://bugs.python.org/issue36216
Vendor advisory: https://bugs.python.org/issue36216
Patch / mitigation: https://bugs.python.org/issue36216
Patch / mitigation: https://github.com/python/cpython/pull/12201
Patch / mitigation: https://python-security.readthedocs.io/vuln/urlsplit-nfkc-normalization.html
Patch / mitigation: https://bugs.python.org/issue36216
Patch / mitigation: https://github.com/python/cpython/pull/12201
Patch / mitigation: https://python-security.readthedocs.io/vuln/urlsplit-nfkc-normalization.html

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 07:06 UTC · record ↗

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