🔴 Critical Vulnerability: CVE-2019-9636 — python, fedoraproject

Vulnerability Snapshot

CVE-2019-9636 is rated CRITICAL — exploitation is trivial or already observed in the wild and impact is severe. Patch immediately, not on the next maintenance window.

Affected technology: python, fedora, leap, debian_linux, ubuntu_linux, plus 5 other product variants.

Executive Summary

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.

Why It Matters

CVE-2019-9636 is rated CRITICAL severity, requiring immediate attention from security teams.

CVSS Base Score: 9.8/10

Affected Technologies

Vendors: python, fedoraproject, opensuse, debian, canonical, redhat, oracle

Products: python, fedora, leap, debian_linux, ubuntu_linux, openshift_container_platform, enterprise_linux, enterprise_linux_desktop, enterprise_linux_eus, enterprise_linux_server, enterprise_linux_server_aus, enterprise_linux_server_eus, enterprise_linux_server_tus, enterprise_linux_workstation, virtualization, sun_zfs_storage_appliance_kit

🛡️What Defenders Should Check

Check if you are affected — Review your asset inventory for products listed in CVE-2019-9636.

Apply available patches — Visit vendor advisories for the latest security updates.

Monitor for exploitation — Check your SIEM/IDS logs for related indicators.

Use Vulnios to continuously monitor your exposure to CVE-2019-9636 and similar vulnerabilities.

References & Sources

http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00092.html

http://lists.opensuse.org/opensuse-security-announce/2019-04/msg00097.html

http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00024.html

http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00050.html

http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00042.html

http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html

http://www.securityfocus.com/bid/107400

https://access.redhat.com/errata/RHBA-2019:0763

https://access.redhat.com/errata/RHBA-2019:0764

https://access.redhat.com/errata/RHBA-2019:0959

How Vulnios Detects This

Vulnios scans for this vulnerability using Trivy and Grype for CVE matching against your container images and OS package manifests. Run a scan against your environment to see whether you are exposed; findings are linked back to the original CVE record so triage starts with the patch path already known.

AI Security Advisor

Get AI-powered security recommendations tailored to this specific threat — including risk assessment, detection guidance, MITRE ATT&CK mapping, and actionable remediation steps.

Affected Products

pythonfedoraleapdebian_linuxubuntu_linuxopenshift_container_platformenterprise_linuxenterprise_linux_desktopenterprise_linux_eusenterprise_linux_server

Sources

NVD / NIST

Related Threat Alerts

Frequently Asked Questions

What is CVE-2019-9636?

CVE-2019-9636 is a critical-severity vulnerability tracked under the Common Vulnerabilities and Exposures program. 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 (cre

Am I affected?

Check whether your environment runs python, fedora, leap, debian_linux, ubuntu_linux. If you operate any of those, treat yourself as in scope until you have evidence otherwise. A Vulnios scan will identify the exact assets carrying the affected version.

How urgent is the response?

Critical: do not wait for your normal patch cycle. Verify exposure today, apply the vendor patch immediately, and add detection rules for any post-exploit indicators.

How do I remediate?

Apply the vendor patch listed in the upstream advisory linked under Sources. If the patch is not yet available, follow the vendor-supplied workaround (often a config flag or feature disable) and add detections for the published exploit pattern in your SIEM. Re-scan after the patch lands to confirm the finding clears.

Where can I track exploitation activity?

Watch CISA's Known Exploited Vulnerabilities catalog for CVE-2019-9636. Cross-reference with public exploit databases and your own SIEM/IDS for indicator-of-compromise patterns. Vulnios tracks KEV status automatically and surfaces it on the asset findings view.

How does Vulnios help with this?

Vulnios continuously cross-references your asset inventory against the live CVE feed (NVD, vendor advisories, CISA KEV, and curated OSINT). When a new CVE matches your environment, you get a prioritized finding with the severity, KEV status, exploit-prediction (EPSS), and a direct path to the vendor patch. You can start a free scan from the homepage.

critical

Protect Your Organization

Monitor CVEs, scan for vulnerabilities, and get real-time threat alerts — all in one platform.

Get Started Free Free Security Scan OSINT Dashboard

Weekly threat digest

KEV-listed exploits and vendor advisories, every Monday.

One email a week. Unsubscribe any time.

Get instant alerts on Telegram

Join our public channel for real-time critical CVE alerts.

Follow @vulnios

Critical Vulnerability: CVE-2019-9636 — python, fedoraproject — python, fedora