Vulnerability · Published Mar 27, 2026 · Assigned by mitre
CVE-2026-34475
Medium 5.4
In plain English
A medium-severity security flaw in Varnish Cache from varnish-software. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)5.4Medium
Exploit odds (30 days)0.2%top 88.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | varnish | no fix listed | DEBIAN-CVE-2026-34475 |
| Debian:13 | varnish | 7.7.0-3+deb13u2 | DEBIAN-CVE-2026-34475 |
| Ubuntu:24.04:LTS | varnish | no fix listed | UBUNTU-CVE-2026-34475 |
| Ubuntu:25.10 | varnish | no fix listed | UBUNTU-CVE-2026-34475 |
| Ubuntu:26.04:LTS | varnish | no fix listed | UBUNTU-CVE-2026-34475 |
| Ubuntu:26.10 | varnish | no fix listed | UBUNTU-CVE-2026-34475 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| varnish-software | Varnish Cache | 0 – before 6.0.17 LTS7.0.0 – before 8.0.1 |
Weakness: CWE-180 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N