CVE-2026-73563

MEDIUMPre-NVD 4.74.7—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (18th percentile of EPSS-scored CVEs). 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, secondary
Trending — 3 sources updated this week
4.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 4.7Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Backstage is an open framework for building developer portals. Prior to 0.29.2, the experimental dynamic client registration and client ID metadata document features in the @backstage/plugin-auth-backend use full-string matcher.isMatch glob matching for auth.experimentalDynamicClientRegistration.allowedRedirectUriPatterns and the auth.experimentalClientIdMetadataDocuments allowedClientIdPatterns and allowedRedirectUriPatterns options. A hostname wildcard can match across URL component boundaries, allowing an attacker-controlled redirect URI with a trusted hostname suffix in its path to pass the allowlist and receive an OAuth authorization code after a victim completes the flow. Patterns without an explicit protocol can match unintended protocols, and redirect URIs containing embedded credentials are accepted after user information is stripped for matching. The features are experimental and disabled by default; only deployments that enable them and configure custom wildcard-hostname or protocol-less patterns are affected. This issue is first fixed in prerelease version 0.29.2.

CVSS v3
4.7
EG Score
4.7MEDIUMmedium confidence
EG Risk
26
EG Risk 26/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity47% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.3%
EPSS %ILE
18th
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact partial (CVSS below 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

August 13, 2026

Last Modified

September 18, 2026

Advisory Details (1)

Auto-updated Aug 13, 2026
Patch available. Sources: github.
githubMentions a patch (unverified)

Unauthenticated OAuth account takeover via `redirect_uri` allowlist bypass in `@backstage/plugin-auth-backend` · Advisory · backstage/backstage · GitHub

https://github.com/backstage/backstage/security/advisories/GHSA-38hq-7x33-php4

Vendor Advisories for CVE-2026-73563(3)

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
redhatansible-automation-platform/automation-portal:17887757482026-09-08redhat
redhatansible-automation-platform/automation-portal:17887835912026-09-08redhat

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

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFix by version rangeDependents
@backstage/plugin-auth-backend—
  • every version up to 0.29.2: fixed in 0.29.2
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 12× in last 7d / 67× 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.

Showing the most recent 100 of 123 total refreshes for this CVE.

  1. 2026-10-10 20:00 UTCEPSS rescore
  2. 2026-10-09 20:07 UTCEPSS rescore
  3. 2026-10-08 17:13 UTCEPSS rescore
  4. 2026-10-07 23:48 UTCEPSS rescore
  5. 2026-10-06 19:27 UTCEG score recompute
  6. 2026-10-06 19:27 UTCVendor advisory
  7. 2026-10-06 15:18 UTCEPSS rescore
  8. 2026-10-05 20:41 UTCEG score recompute
  9. 2026-10-05 20:41 UTCVendor advisory
  10. 2026-10-05 17:43 UTCEPSS rescore
  11. 2026-10-04 23:22 UTCEPSS rescore
  12. 2026-10-04 22:19 UTCVendor advisory
  13. 2026-10-03 19:48 UTCEG score recompute
  14. 2026-10-03 19:48 UTCVendor advisory
  15. 2026-10-03 14:26 UTCEPSS rescore
  16. 2026-10-02 07:32 UTCEG score recompute
  17. 2026-10-02 07:32 UTCVendor advisory
  18. 2026-10-01 19:50 UTCEPSS rescore
  19. 2026-09-30 21:46 UTCEG score recompute
  20. 2026-09-30 21:46 UTCVendor advisory
  21. 2026-09-29 15:24 UTCEPSS rescore
  22. 2026-09-29 06:36 UTCEG score recompute
  23. 2026-09-29 06:36 UTCVendor advisory
  24. 2026-09-28 13:52 UTCEPSS rescore
  25. 2026-09-28 08:11 UTCEG score recompute
Show 75 more
  1. 2026-09-28 08:11 UTCVendor advisory
  2. 2026-09-27 13:48 UTCEPSS rescore
  3. 2026-09-27 09:43 UTCEG score recompute
  4. 2026-09-27 09:43 UTCVendor advisory
  5. 2026-09-26 15:59 UTCEPSS rescore
  6. 2026-09-25 09:54 UTCEG score recompute
  7. 2026-09-25 09:54 UTCVendor advisory
  8. 2026-09-24 11:32 UTCEG score recompute
  9. 2026-09-24 11:32 UTCVendor advisory
  10. 2026-09-23 17:54 UTCEPSS rescore
  11. 2026-09-23 13:10 UTCEG score recompute
  12. 2026-09-23 13:10 UTCVendor advisory
  13. 2026-09-22 14:48 UTCEG score recompute
  14. 2026-09-22 14:48 UTCVendor advisory
  15. 2026-09-21 21:09 UTCEPSS rescore
  16. 2026-09-21 16:21 UTCEG score recompute
  17. 2026-09-21 16:21 UTCVendor advisory
  18. 2026-09-20 20:16 UTCEPSS rescore
  19. 2026-09-20 17:21 UTCVendor advisory
  20. 2026-09-19 18:59 UTCEG score recompute
  21. 2026-09-19 18:59 UTCVendor advisory
  22. 2026-09-18 20:10 UTCEG score recompute
  23. 2026-09-18 20:10 UTCVendor advisory
  24. 2026-09-18 19:28 UTCEPSS rescore
  25. 2026-09-17 22:21 UTCEG score recompute
  26. 2026-09-17 22:21 UTCVendor advisory
  27. 2026-09-16 23:59 UTCEG score recompute
  28. 2026-09-16 23:59 UTCVendor advisory
  29. 2026-09-16 14:08 UTCEPSS rescore
  30. 2026-09-16 05:15 UTCEPSS rescore
  31. 2026-09-15 20:06 UTCEG score recompute
  32. 2026-09-15 20:06 UTCVendor advisory
  33. 2026-09-15 03:12 UTCEPSS rescore
  34. 2026-09-14 20:49 UTCVendor advisory
  35. 2026-09-13 21:24 UTCEG score recompute
  36. 2026-09-13 21:24 UTCVendor advisory
  37. 2026-09-12 23:02 UTCEG score recompute
  38. 2026-09-12 23:02 UTCVendor advisory
  39. 2026-09-12 15:02 UTCEPSS rescore
  40. 2026-09-12 00:04 UTCEG score recompute
  41. 2026-09-12 00:04 UTCVendor advisory
  42. 2026-09-11 14:53 UTCEPSS rescore
  43. 2026-09-11 01:41 UTCEG score recompute
  44. 2026-09-11 01:41 UTCVendor advisory
  45. 2026-09-10 09:35 UTCEPSS rescore
  46. 2026-09-10 03:19 UTCVendor advisory
  47. 2026-09-09 04:56 UTCEG score recompute
  48. 2026-09-09 04:56 UTCVendor advisory
  49. 2026-09-08 22:01 UTCEPSS rescore
  50. 2026-09-07 19:37 UTCEG score recompute
  51. 2026-09-06 21:15 UTCEG score recompute
  52. 2026-09-06 13:48 UTCEPSS rescore
  53. 2026-09-05 22:52 UTCEG score recompute
  54. 2026-09-05 00:30 UTCEG score recompute
  55. 2026-09-04 05:07 UTCEPSS rescore
  56. 2026-09-03 01:02 UTCEG score recompute
  57. 2026-09-02 14:12 UTCEPSS rescore
  58. 2026-09-02 01:49 UTCEG score recompute
  59. 2026-09-01 13:54 UTCEPSS rescore
  60. 2026-09-01 04:40 UTCEPSS rescore
  61. 2026-09-01 04:40 UTCEPSS rescore
  62. 2026-08-31 04:18 UTCEG score recompute
  63. 2026-08-30 19:18 UTCEPSS rescore
  64. 2026-08-30 19:17 UTCEPSS rescore
  65. 2026-08-30 05:56 UTCEG score recompute
  66. 2026-08-30 01:22 UTCEPSS rescore
  67. 2026-08-29 07:33 UTCEG score recompute
  68. 2026-08-28 21:42 UTCEPSS rescore
  69. 2026-08-27 19:32 UTCEG score recompute
  70. 2026-08-27 14:25 UTCEPSS rescore
  71. 2026-08-26 20:52 UTCEG score recompute
  72. 2026-08-26 14:47 UTCEPSS rescore
  73. 2026-08-25 22:13 UTCEG score recompute
  74. 2026-08-25 13:49 UTCEPSS rescore
  75. 2026-08-24 23:50 UTCEG score recompute

Related CVEs(same product + same vendor + same CWE)

Same product

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npm:@backstage/plugin-auth-backend

Frequently asked(5)

What is CVE-2026-73563?
CVE-2026-73563 is a medium vulnerability published on August 13, 2026. Backstage is an open framework for building developer portals. Prior to 0.29.2, the experimental dynamic client registration and client ID metadata document features in the @backstage/plugin-auth-backend use full-string matcher.isMatch glob matching for…
When was CVE-2026-73563 disclosed?
CVE-2026-73563 was first published on August 13, 2026, with the most recent update on September 18, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73563 actively exploited?
CVE-2026-73563 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (18th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-73563?
CVE-2026-73563 has a CVSS base score of 4.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-73563?
A fix for CVE-2026-73563 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-73563 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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