What is CVE-2026-55202?

CVE-2026-55202 is a high-severity vulnerability in Tinyproxy, classified under Authentication Bypass by Spoofing. CVSS score: 8.2/10. Published 2026-06-17.

How severe is CVE-2026-55202?

High severity. CVSS v3 base score is 8.2 out of 10.

Vulnerability in Tinyproxy

CVE-2026-55202

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.

Published 2026-06-17 · last modified 2026-07-14.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (45.2th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.006 · change: +0.002

Affected products

Tinyproxy — versions 0, 09312a185ae25cc486b4ff5987638a7917a48bce

Weakness classification (CWE)

CWE-290 — Authentication Bypass by Spoofing

References

github.com/tinyproxy/tinyproxy/pull/606 (issue-tracking)
github.com/tinyproxy/tinyproxy/commit/09312a185ae25cc486b4ff5987638a7917a48bce (patch)
www.vulncheck.com/advisories/evil-winrm-path-traversal-in-download-dir-function (third-party-advisory)

Frequently asked questions

What is CVE-2026-55202?: CVE-2026-55202 is a high-severity vulnerability in Tinyproxy, classified under Authentication Bypass by Spoofing. CVSS score: 8.2/10. Published 2026-06-17.
How severe is CVE-2026-55202?: High severity. CVSS v3 base score is 8.2 out of 10.