# CVE-2026-55202: Tinyproxy - Stathost Detection Bypass via Host Header Manipulation

> Unauthenticated attackers can bypass stathost access controls in Tinyproxy by manipulating Host headers or ports, gaining unauthorized access to internal statistics.

- **Severity:** High 8.8 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Jun 2026
- **Updated:** 29 Oct 2026
- **Also known as:** DEBIAN-CVE-2026-55202, GHSA-f33v-8wrm-6584, UBUNTU-CVE-2026-55202

## What is CVE-2026-55202?

CVE-2026-55202 is a high-severity authentication bypass vulnerability in tinyproxy, published on 17 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Tinyproxy through 1.11.3, fixed in commit 09312a1, fails to properly validate the Host header during stathost detection, allowing unauthenticated attackers to access the stats page by injecting a matching Host header or bypass detection via port manipulation. Remote attackers can trigger unauthorized access to internal proxy statistics or misroute requests as transparent proxy connections to circumvent access controls.

Weakness: CWE-290 (Authentication Bypass by Spoofing)

## Which versions are affected by CVE-2026-55202?


## How do I fix CVE-2026-55202?

Apply the vendor's patch.

## Is CVE-2026-55202 being exploited?

There is no known exploitation of CVE-2026-55202 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55202 and fix it if it is affected.

What it is: CVE-2026-55202 is a high-severity authentication bypass vulnerability in tinyproxy, published on 17 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-55202 in the wild and no public exploit code.

Affected product: tinyproxy. 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-2026-55202/ (Markdown: https://insights.sbomify.com/CVE-2026-55202/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55202
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55202
- OSV: https://osv.dev/vulnerability/CVE-2026-55202

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55202/
Summaries are generated and may contain mistakes; the official description above is the record.