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.
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.004 (29.1th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.004 · change: +0.002
Affected products
- Varnish-Software Varnish Cache — versions 0, 7.0.0
- Varnish-Software Varnish Enterprise — versions 6.0.16
- Vinyl-Cache Vinyl Cache
Weakness classification (CWE)
Public proof-of-concept exploits
References
- vinyl-cache.org/security/VSV00018.html (Mitigation, Vendor Advisory)
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.