CVE-2020-27847

Name: CVE-2020-27847
Creator: NVD / NIST
Published: 2021-05-28T11:15:07.703+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 1.72%

Last modified Jun 17, 2026

CVE-2020-27847 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. A vulnerability exists in the SAML connector of the github.com/dexidp/dex library used to process SAML Signature Validation. This flaw allows an attacker to bypass SAML authentication. EPSS estimates a 1.72% chance of exploitation in the next 30 days.

Description

A vulnerability exists in the SAML connector of the github.com/dexidp/dex library used to process SAML Signature Validation. This flaw allows an attacker to bypass SAML authentication. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability. This flaw affects dex versions before 2.27.0.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

1.72%

74.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-228

Affected Software

Vendor	Product	Versions
Linuxfoundation	Dex	< 2.27.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1907732Issue Tracking, Third Party Advisory
https://github.com/dexidp/dex/security/advisories/GHSA-m9hp-7r99-94h5Patch, Third Party Advisory
https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities/Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1907732Issue Tracking, Third Party Advisory
https://github.com/dexidp/dex/security/advisories/GHSA-m9hp-7r99-94h5Patch, Third Party Advisory
https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities/Vendor Advisory

Timeline

Published: May 28, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-27847?

How severe is CVE-2020-27847?

CVE-2020-27847 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 1.72% probability of exploitation in the next 30 days.

How do I fix CVE-2020-27847?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-27847?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST