CVE-2020-26290

CRITICALNVD 9.39.3
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to NVD's CVSS score.

Score 9.3 from GitHub Security Advisory (severity: CRITICAL) published 2021-12-20. NVD baseline CVSS 9.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, NVD CVSS v3

Also known asEUVD-2021-2551 (ENISA EUVD) · GHSA-m9hp-7r99-94h5 (GitHub Security Advisories)Source: ENISA EUVD

9.3EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 1.0%CVSS: 9.3Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

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
9.3CRITICALmedium confidence
EG Risk
42
EG Risk 42/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity93% × 45%
Impact severity (EG Severity): CVSS 9.3 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation1.0% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines.
EPSS PROB
1.0%
EPSS %ILE
63rd
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (9.3): severity, escalated by confirmed exploitation. This CVE's 9.3 is its impact severity (EG Severity), not escalated.

EG Severity
9.3 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
1.0% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-12). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Track* at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

December 28, 2020

Last Modified

November 21, 2024

Advisory Details (8)

Auto-updated Sep 15, 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
Web page

Coordinated disclosure of XML round-trip vulnerabilities in Go library

https://mattermost.com/blog/coordinated-disclosure-go-xml-vulnerabilities/
GitHub advisoryMentions a patch (unverified)

Signature Validation Bypass · Advisory · russellhaering/goxmldsig · GitHub

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

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
Web page

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
Web page

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 advisoryMentions a patch (unverified)

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

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

Vendor Advisories for CVE-2020-26290(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
gogithub.com/dexidp/dex @ 2.27.0 (fixes < 2.27.0)—ghsa
gogithub.com/russellhaering/goxmldsig @ 1.1.0 (fixes < 1.1.0)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(2 across 1 ecosystem)
Go(2)
PackageVulnerable rangeFix by version rangeDependents
github.com/dexidp/dex—
  • every version up to 2.27.0: fixed in 2.27.0
—
github.com/russellhaering/goxmldsig—
  • every version up to 1.1.0: fixed in 1.1.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 44× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed its CVE.org record (CNA or CISA ADP). An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). "EchelonGraph re-scored" is our own recompute of this CVE's score, not an update from a source, and is not counted in the refreshes above. Most recent first.

Showing the most recent 100 of 240 rows on record for this CVE, as 99 entries (1 repeat merged).

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 100 is merged into the row it repeats. The 140 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-13 16:39 UTCEPSS rescoreEPSS 1.0% · 63rd percentile
  2. 2026-11-13 13:46 UTCEchelonGraph re-scored
  3. 2026-11-13 13:46 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  4. 2026-11-12 16:29 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  5. 2026-11-12 11:45 UTCEchelonGraph re-scored
  6. 2026-11-12 11:45 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  7. 2026-11-11 16:31 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  8. 2026-11-11 09:46 UTCEchelonGraph re-scored
  9. 2026-11-11 09:46 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  10. 2026-11-10 16:34 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  11. 2026-11-10 07:45 UTCEchelonGraph re-scored
  12. 2026-11-10 07:45 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  13. 2026-11-09 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  14. 2026-11-09 05:46 UTCEchelonGraph re-scored
  15. 2026-11-09 05:46 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  16. 2026-11-08 16:32 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  17. 2026-11-08 03:45 UTCEchelonGraph re-scored
  18. 2026-11-08 03:45 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  19. 2026-11-07 16:33 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  20. 2026-11-07 01:45 UTCEchelonGraph re-scored
  21. 2026-11-07 01:45 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  22. 2026-11-06 16:29 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  23. 2026-11-05 23:46 UTCEchelonGraph re-scored
  24. 2026-11-05 23:46 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  25. 2026-11-05 16:30 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
Show 74 more
  1. 2026-11-04 21:47 UTCEchelonGraph re-scored
  2. 2026-11-04 21:47 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  3. 2026-11-04 16:29 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  4. 2026-11-03 19:47 UTCEchelonGraph re-scored
  5. 2026-11-03 19:47 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  6. 2026-11-03 16:36 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  7. 2026-11-03 11:25 UTCOSV refresh
  8. 2026-11-02 17:48 UTCEchelonGraph re-scored
  9. 2026-11-02 17:48 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  10. 2026-11-02 16:36 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  11. 2026-11-01 16:29 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  12. 2026-11-01 15:48 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  13. 2026-11-01 08:36 UTCGHSA enrichmentGHSA-m9hp-7r99-94h5 · GitHub severity CRITICAL · GitHub CVSS 9.3
  14. 2026-11-01 08:36 UTCEchelonGraph re-scored
  15. 2026-10-31 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  16. 2026-10-31 13:48 UTCEchelonGraph re-scored
  17. 2026-10-30 16:29 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  18. 2026-10-30 11:48 UTCEchelonGraph re-scored
  19. 2026-10-29 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  20. 2026-10-29 09:48 UTCEchelonGraph re-scored
  21. 2026-10-28 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  22. 2026-10-28 07:49 UTCEchelonGraph re-scored
  23. 2026-10-27 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  24. 2026-10-27 05:50 UTCEchelonGraph re-scored
  25. 2026-10-26 16:27 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  26. 2026-10-25 18:46 UTCEchelonGraph re-scored
  27. 2026-10-25 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  28. 2026-10-24 21:39 UTCEchelonGraph re-scored
  29. 2026-10-24 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  30. 2026-10-23 19:39 UTCEchelonGraph re-scored
  31. 2026-10-23 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  32. 2026-10-22 17:39 UTCEchelonGraph re-scored
  33. 2026-10-22 16:29 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  34. 2026-10-21 16:28 UTCEPSS rescoreEPSS 1.0% · 62nd percentile
  35. 2026-10-21 15:36 UTCEchelonGraph re-scored
  36. 2026-10-20 16:28 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  37. 2026-10-20 13:37 UTCEchelonGraph re-scored
  38. 2026-10-19 16:27 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  39. 2026-10-19 11:36 UTCEchelonGraph re-scored
  40. 2026-10-18 16:28 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  41. 2026-10-18 09:26 UTCEchelonGraph re-scored
  42. 2026-10-17 16:28 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  43. 2026-10-17 07:26 UTCEchelonGraph re-scored
  44. 2026-10-16 16:33 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  45. 2026-10-16 05:26 UTCEchelonGraph re-scored
  46. 2026-10-15 16:27 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  47. 2026-10-15 03:25 UTCEchelonGraph re-scored
  48. 2026-10-14 16:28 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  49. 2026-10-13 23:35 UTCEchelonGraph re-scored
  50. 2026-10-13 16:28 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  51. 2026-10-12 19:39 UTCEchelonGraph re-scored
  52. 2026-10-12 16:29 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  53. 2026-10-12 00:02 UTCEchelonGraph re-scored
  54. 2026-10-11 13:43 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  55. 2026-10-10 19:56 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  56. 2026-10-09 20:04 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  57. 2026-10-08 16:38 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  58. 2026-10-07 23:44 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  59. 2026-10-06 15:13 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  60. 2026-10-05 17:39 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  61. 2026-10-04 23:18 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  62. 2026-10-03 14:22 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  63. 2026-09-30 15:16 UTCEchelonGraph re-scored
  64. 2026-09-30 14:59 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  65. 2026-09-29 15:14 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  66. 2026-09-27 13:41 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  67. 2026-09-26 16:20 UTCOSV refresh
  68. 2026-09-26 15:54 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  69. 2026-09-24 14:00 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  70. 2026-09-22 14:43 UTCEPSS rescoreEPSS 1.0% · 61st percentile
  71. 2026-09-21 20:28 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  72. 2026-09-20 20:11 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  73. 2026-09-19 15:37 UTCEPSS rescoreEPSS 1.0% · 60th percentile
  74. 2026-09-18 19:23 UTCEPSS rescoreEPSS 1.0% · 60th percentile

Frequently asked(5)

What is CVE-2020-26290?
CVE-2020-26290 is a critical-severity vulnerability; its CVE record was 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 the CVE record for CVE-2020-26290 published?
The CVE record for CVE-2020-26290 was published on December 28, 2020. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of November 21, 2024; the record at its source may have been updated since.
Is CVE-2020-26290 actively exploited?
CVE-2020-26290 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1.0% probability of exploitation in the next 30 days (63rd percentile of EPSS-scored CVEs).
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?
A fix for CVE-2020-26290 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2020-26290 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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