CVE-2020-26290

CRITICALNVD 9.39.3—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.3 under NVD CVSS v3. EPSS exploit probability: 1.0%, top 42% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 3 sources updated this week
9.3
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 1%CVSS: 9.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Dex is a federated OpenID Connect provider written in Go. In Dex before version 2.27.0 there is a critical set of vulnerabilities which impacts users leveraging the SAML connector. The vulnerabilities enables potential signature bypass due to issues with XML encoding in the underlying Go library. The vulnerabilities have been addressed in version 2.27.0 by using the xml-roundtrip-validator from Mattermost (see related references).

CVSS v3
9.3
EG Score
9.3(medium)
EG Risk
—
EPSS
58.4%
KEV
Not listed

Published

December 28, 2020

Last Modified

November 21, 2024

Advisory Details (8)

Auto-updated Jul 17, 2026
Patch available. Sources: github_commit, github_release, github.
github_release Patch Available

v2.27.0

Patch available: dexidp/dex v2.27.0

https://github.com/dexidp/dex/releases/tag/v2.27.0
github_commit Patch Available

commit 324b1c886b40 (dexidp/dex)

Patch available: dexidp/dex v2.30.1 (contains commit 324b1c886b40)

https://github.com/dexidp/dex/commit/324b1c886b407594196113a3dbddebe38eecd4e8
generic

Coordinated disclosure of XML round-trip vulnerabilities in Go library

https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities/
github Patch Available

Signature Validation Bypass · Advisory · russellhaering/goxmldsig · GitHub

https://github.com/russellhaering/goxmldsig/security/advisories/GHSA-q547-gmf8-8jr7
generic

xml-roundtrip-validator/advisories/unstable-elements.md at master · mattermost/xml-roundtrip-validator · GitHub

https://github.com/mattermost/xml-roundtrip-validator/blob/master/advisories/unstable-elements.md
generic

xml-roundtrip-validator/advisories/unstable-directives.md at master · mattermost/xml-roundtrip-validator · GitHub

https://github.com/mattermost/xml-roundtrip-validator/blob/master/advisories/unstable-directives.md
generic

xml-roundtrip-validator/advisories/unstable-attributes.md at master · mattermost/xml-roundtrip-validator · GitHub

https://github.com/mattermost/xml-roundtrip-validator/blob/master/advisories/unstable-attributes.md
github Patch Available

Critical security issues in XML encoding · Advisory · dexidp/dex · GitHub

https://github.com/dexidp/dex/security/advisories/GHSA-m9hp-7r99-94h5

Affected Packages

(2 across 1 ecosystem)
Go(2)
PackageVulnerable rangeFixed inDependents
github.com/dexidp/dex—2.27.0—
github.com/russellhaering/goxmldsig—1.1.0—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 12× in last 7d / 43× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 22:37 UTCEG score recompute
  2. 2026-07-22 14:05 UTCEPSS rescore
  3. 2026-07-21 15:22 UTCEPSS rescore
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  9. 2026-07-19 04:52 UTCOSV refresh
  10. 2026-07-19 02:26 UTCEPSS rescore
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  1. 2026-07-06 16:25 UTCEPSS rescore
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  5. 2026-07-04 06:29 UTCEPSS rescore
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  7. 2026-07-01 11:33 UTCOSV refresh
  8. 2026-06-30 23:20 UTCEPSS rescore
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  23. 2026-06-21 01:57 UTCEPSS rescore
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  33. 2026-06-13 18:43 UTCOSV refresh
  34. 2026-06-12 23:10 UTCEPSS rescore
  35. 2026-06-11 13:58 UTCEPSS rescore
  36. 2026-06-10 22:16 UTCEPSS rescore
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  38. 2026-06-08 14:15 UTCEPSS rescore
  39. 2026-06-07 15:23 UTCEPSS rescore
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  42. 2026-06-06 13:46 UTCEPSS rescore
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  44. 2026-06-05 22:45 UTCEPSS rescore
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  57. 2026-05-29 13:42 UTCEPSS rescore
  58. 2026-05-28 13:43 UTCEPSS rescore
  59. 2026-05-28 13:43 UTCEPSS rescore
  60. 2026-05-27 13:39 UTCEPSS rescore
  61. 2026-05-26 22:57 UTCEG score recompute
  62. 2026-05-26 13:42 UTCEPSS rescore
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  64. 2026-05-26 07:17 UTCEPSS rescore
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  66. 2026-05-24 16:48 UTCEPSS rescore

Frequently asked(5)

What is CVE-2020-26290?
CVE-2020-26290 is a critical vulnerability published on December 28, 2020. Dex is a federated OpenID Connect provider written in Go. In Dex before version 2.27.0 there is a critical set of vulnerabilities which impacts users leveraging the SAML connector. The vulnerabilities enables potential signature bypass due to issues with XML encoding in the underlying Go library.…
When was CVE-2020-26290 disclosed?
CVE-2020-26290 was first published in the National Vulnerability Database on December 28, 2020, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2020-26290 actively exploited?
CVE-2020-26290 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 58.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2020-26290?
CVE-2020-26290 has a CVSS v3 base score of 9.3 (NVD).
How do I remediate CVE-2020-26290?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2020-26290, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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