CVE-2026-34475

Name: CVE-2026-34475
Creator: NVD / NIST
Published: 2026-03-27T20:16:36.39+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.20%

Last modified Jun 17, 2026

CVE-2026-34475 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass.. EPSS estimates a 0.20% chance of exploitation in the next 30 days.

Description

Varnish Cache before 8.0.1 and Varnish Enterprise before 6.0.16r12, in certain unchecked req.url scenarios, mishandle URLs with a path of / for HTTP/1.1, potentially leading to cache poisoning or authentication bypass.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.20%

10.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-180

Affected Software

Vendor	Product	Versions	Update
Varnish-Software	Varnish Enterprise	<= 6.0.15	—
Varnish-Software	Varnish Enterprise	6.0.16	R1
Vinyl-Cache	Vinyl Cache	< 8.0.1	—

References

https://vinyl-cache.org/security/VSV00018.htmlMitigation, Vendor Advisory

Timeline

Published: Mar 27, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-34475?

How severe is CVE-2026-34475?

CVE-2026-34475 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.20% probability of exploitation in the next 30 days.

How do I fix CVE-2026-34475?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-34475?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST