CVE-2026-34475
Varnish Cache: Varnish Cache and Varnish Enterprise: Cache poisoning and authentication bypass via unchecked URL handling
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 28, 2026
Updated · June 30, 2026
Description
A flaw was found in Varnish Cache and Varnish Enterprise. A remote attacker could exploit this vulnerability by sending specially crafted HTTP/1.1 requests with a path of / in the URL. This mishandling of URLs, specifically in unchecked req.url scenarios, could lead to cache poisoning, where an attacker manipulates cached content, or an authentication bypass, allowing unauthorized access.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
CWE-1286 · Improper Validation of Syntactic Correctness of Input