What is CVE-2026-34475?

CVE-2026-34475 is a medium-severity vulnerability in Varnish-software Varnish Cache, classified under CWE-180. CVSS score: 5.4/10. Published 2026-03-27.

How severe is CVE-2026-34475?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Is CVE-2026-34475 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Vulnerability in Varnish-software Varnish Cache

CVE-2026-34475

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: 0.001 (20.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N.

Affected products

Varnish-software Varnish Cache — versions 0, 7.0.0

Weakness classification (CWE)

CWE-180

Public proof-of-concept exploits

bitbcybr/way2poc_cve-2026-34475

References

vinyl-cache.org/security/VSV00018.html

Frequently asked questions

What is CVE-2026-34475?: CVE-2026-34475 is a medium-severity vulnerability in Varnish-software Varnish Cache, classified under CWE-180. CVSS score: 5.4/10. Published 2026-03-27.
How severe is CVE-2026-34475?: Medium severity. CVSS v3 base score is 5.4 out of 10.
Is CVE-2026-34475 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.