CVE-2026-39858

high Red Hat
CVSS v3 Base Score
8.2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS Score
0.1%
Exploitation probability in 30 days
Top 76% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Confidentiality
High
Integrity
Low
Availability
None
Published: April 30, 2026 (70 days ago)
Last Modified: April 30, 2026
Vendor: Red Hat
Source: REDHAT

Description

A flaw was found in Traefik. A remote attacker can exploit an authentication bypass vulnerability by injecting spoofed trust context through unsanitized alias headers. This is due to Traefik's forwarded-header sanitization logic not properly handling alias header names that use underscores instead of dashes. This allows an attacker to bypass authentication on protected routes without valid credentials.

CWE

CWE-289

Affected Products

Red Hat OpenShift Dev Spaces

References

🔗 bugzilla.redhat.com 🔗 www.cve.org 🔗 nvd.nist.gov 🔗 github.com 🔗 github.com