What is CVE-2020-26178?

CVE-2020-26178 is a medium-severity vulnerability in Tangro Business Workflow, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.3/10. Published 2020-12-18.

How severe is CVE-2020-26178?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Auth bypass in Tangro Business Workflow

CVE-2020-26178

In tangro Business Workflow before 1.18.1, knowing an attachment ID, it is possible to download workitem attachments without being authenticated.

Vulnerability class: IDOR (Insecure Direct Object Reference)

Published 2020-12-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.009 (58.0th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: +0.000

Affected products

Tangro Business Workflow

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

www.tangro.de/ (Product)
blog.to.com/advisory-tangro-bwf-1-17-5-multiple-vulnerabilities/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2020-26178?: CVE-2020-26178 is a medium-severity vulnerability in Tangro Business Workflow, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 5.3/10. Published 2020-12-18.
How severe is CVE-2020-26178?: Medium severity. CVSS v3 base score is 5.3 out of 10.