# 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 /


- **Severity:** Medium 5.4 (`CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N`)
- **Exploited in the wild:** Not known
- **Fix available:** Yes
- **Published:** 27 Mar 2026
- **Updated:** 27 Mar 2026
- **Also known as:** DEBIAN-CVE-2026-34475, GHSA-m9gq-cmcj-p62x, OESA-2026-2677, OESA-2026-3045, ROOT-OS-DEBIAN-11-CVE-2026-34475, ROOT-OS-DEBIAN-12-CVE-2026-34475, UBUNTU-CVE-2026-34475

## What is CVE-2026-34475?

CVE-2026-34475 is a medium-severity vulnerability in varnish-software Varnish Cache, published on 27 Mar 2026. 

### 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.

Weakness: CWE-180 (Incorrect Behavior Order: Validate Before Canonicalize)

## Which versions are affected by CVE-2026-34475?

It affects 2 products.


Products: Varnish-Software Varnish Enterprise, Vinyl-Cache Vinyl Cache.

## How do I fix CVE-2026-34475?

Upgrade to a fixed version.

## Is CVE-2026-34475 being exploited?

There is no known exploitation of CVE-2026-34475 in the wild and no public exploit code.

## Other vulnerabilities in varnish-software Varnish Cache

- [CVE-2023-41104](https://insights.sbomify.com/CVE-2023-41104/): Memory corruption in n/a (medium 6.5)
- [CVE-2025-30346](https://insights.sbomify.com/CVE-2025-30346/): Other in Varnish Cache (medium 5.4)
- [CVE-2026-40394](https://insights.sbomify.com/CVE-2026-40394/): Denial of service in Varnish Cache (medium 4.0)
- [CVE-2026-40395](https://insights.sbomify.com/CVE-2026-40395/): Denial of service in Varnish Enterprise (medium 4.0)
- [CVE-2025-30347](https://insights.sbomify.com/CVE-2025-30347/): Information disclosure in Varnish Enterprise (medium 4.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34475 and fix it if it is affected.

What it is: CVE-2026-34475 is a medium-severity vulnerability in varnish-software Varnish Cache, published on 27 Mar 2026. 
Exploitation: There is no known exploitation of CVE-2026-34475 in the wild and no public exploit code.

Affected product: varnish-software Varnish Cache. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34475/ (Markdown: https://insights.sbomify.com/CVE-2026-34475/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34475
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34475
- OSV: https://osv.dev/vulnerability/CVE-2026-34475

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34475/
Summaries are generated and may contain mistakes; the official description above is the record.