CVE-2020-1045: Fedoraproject Fedora

High severity, CVSS 7.5. EPSS: 5.9% chance of exploitation in the next 30 days.

<p>A security feature bypass vulnerability exists in the way Microsoft ASP.NET Core parses encoded cookie names.</p> <p>The ASP.NET Core cookie parser decodes entire cookie strings which could allow a malicious attacker to set a second cookie with the name being percent encoded.</p> <p>The security update addresses the vulnerability by fixing the way the ASP.NET Core cookie parser handles encoded names.</p>

Affected products

• Fedoraproject Fedora: version 32 only; version 33 only
• Microsoft ASP.NET Core: from 2.1, up to and including 2.1.21; from 3.1, before 3.1.8 (fixed in 3.1.8)
• Red Hat Enterprise Linux: version 8.0 only
• Red Hat Enterprise Linux Aus: version 8.2 only; version 8.4 only; version 8.6 only
• Red Hat Enterprise Linux Eus: version 8.2 only; version 8.4 only; version 8.6 only
• Red Hat Enterprise Linux Tus: version 8.2 only; version 8.4 only; version 8.6 only

Published 2020-09-11. Last modified 2026-06-17.