CVE-2026-73563

MEDIUMNVD 6.16.1
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.1 under NVD CVSS v3. EPSS exploit probability: 0.2% (6th percentile of EPSS-scored CVEs). GitHub Security Advisory CVSS 4.7 is lower than this score; a lower GitHub score revises it only when its advisory is newer than the CVE record's last change, and this advisory (published 2026-07-24) is not newer than that change (2026-10-15), so it does not.

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

Also known asEUVD-2026-58177 (ENISA EUVD) · GHSA-38hq-7x33-php4 (GitHub Security Advisories)Source: ENISA EUVD

6.1EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 6.1Exploit: 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
6.1
EG Score
6.1MEDIUMmedium confidence
EG Risk
28
EG Risk 28/100

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)
Severity61% × 45%
Impact severity (EG Severity): CVSS 6.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at every mission impact level.
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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
0.2%
EPSS %ILE
6th
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 (6.1): severity, escalated by confirmed exploitation. This CVE's 6.1 is its impact severity (EG Severity), not escalated.

EG Severity
6.1 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.NVD CVSS v3 · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). 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 every mission impact level.CISA BOD 26-04: 60 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 every mission impact level.

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

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (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)60 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 Vulnrichment) · Technical impact partial (CISA Vulnrichment). 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

August 13, 2026

Last Modified

October 15, 2026

Advisory Details (1)

Auto-updated Aug 13, 2026
Patch available. Sources: github.
GitHub advisoryMentions 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(3)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatansible-automation-platform/automation-portal:17887757482026-09-08redhat
redhatansible-automation-platform/automation-portal:17887835912026-09-08redhat
npm@backstage/plugin-auth-backend @ 0.29.2 (fixes <= 0.29.1)—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

(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 7× in last 7d / 33× 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 167 rows on record for this CVE.

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. None are among the latest 100 rows. The 67 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  2. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-11-10 16:45 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  4. 2026-11-09 16:36 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  5. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  6. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  7. 2026-11-06 16:39 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  9. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  10. 2026-11-03 16:49 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  11. 2026-11-02 16:46 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  12. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  13. 2026-11-01 07:39 UTCGHSA enrichmentGHSA-38hq-7x33-php4 · GitHub severity MODERATE · GitHub CVSS 4.7
  14. 2026-11-01 07:39 UTCEchelonGraph re-scored
  15. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  16. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  17. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  18. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  19. 2026-10-27 18:55 UTCOSV refresh
  20. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  21. 2026-10-26 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  22. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  23. 2026-10-25 14:05 UTCEchelonGraph re-scored
  24. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  25. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
Show 75 more
  1. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  2. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  3. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  4. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  5. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  6. 2026-10-18 03:15 UTCEchelonGraph re-scored
  7. 2026-10-16 16:44 UTCEPSS rescoreEPSS 0.2% · 6th percentile
  8. 2026-10-15 20:47 UTCEchelonGraph re-scored▲ 1.40
  9. 2026-10-15 20:47 UTCVendor advisory
  10. 2026-10-15 20:45 UTCNVD updateCVSS v3 → 6.1
  11. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  12. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  13. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  14. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  15. 2026-10-12 15:40 UTCEchelonGraph re-scored
  16. 2026-10-11 19:26 UTCEchelonGraph re-scored
  17. 2026-10-11 16:42 UTCEchelonGraph re-scored
  18. 2026-10-11 14:01 UTCEchelonGraph re-scored
  19. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 19th percentile
  20. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  21. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  22. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  23. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  24. 2026-10-06 19:27 UTCEchelonGraph re-scored
  25. 2026-10-06 19:27 UTCVendor advisory
  26. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  27. 2026-10-05 20:41 UTCEchelonGraph re-scored
  28. 2026-10-05 20:41 UTCVendor advisory
  29. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  30. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  31. 2026-10-04 22:19 UTCVendor advisory
  32. 2026-10-03 19:48 UTCEchelonGraph re-scored
  33. 2026-10-03 19:48 UTCVendor advisory
  34. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  35. 2026-10-02 07:32 UTCEchelonGraph re-scored
  36. 2026-10-02 07:32 UTCVendor advisory
  37. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  38. 2026-09-30 21:46 UTCEchelonGraph re-scored
  39. 2026-09-30 21:46 UTCVendor advisory
  40. 2026-09-29 15:24 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  41. 2026-09-29 06:36 UTCEchelonGraph re-scored
  42. 2026-09-29 06:36 UTCVendor advisory
  43. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  44. 2026-09-28 08:11 UTCEchelonGraph re-scored
  45. 2026-09-28 08:11 UTCVendor advisory
  46. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  47. 2026-09-27 09:43 UTCEchelonGraph re-scored
  48. 2026-09-27 09:43 UTCVendor advisory
  49. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 18th percentile
  50. 2026-09-25 09:54 UTCEchelonGraph re-scored
  51. 2026-09-25 09:54 UTCVendor advisory
  52. 2026-09-24 11:32 UTCEchelonGraph re-scored
  53. 2026-09-24 11:32 UTCVendor advisory
  54. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  55. 2026-09-23 13:10 UTCEchelonGraph re-scored
  56. 2026-09-23 13:10 UTCVendor advisory
  57. 2026-09-22 14:48 UTCEchelonGraph re-scored
  58. 2026-09-22 14:48 UTCVendor advisory
  59. 2026-09-21 21:09 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  60. 2026-09-21 16:21 UTCEchelonGraph re-scored
  61. 2026-09-21 16:21 UTCVendor advisory
  62. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  63. 2026-09-20 17:21 UTCVendor advisory
  64. 2026-09-19 18:59 UTCEchelonGraph re-scored
  65. 2026-09-19 18:59 UTCVendor advisory
  66. 2026-09-18 20:10 UTCEchelonGraph re-scored
  67. 2026-09-18 20:10 UTCVendor advisory
  68. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  69. 2026-09-17 22:21 UTCEchelonGraph re-scored
  70. 2026-09-17 22:21 UTCVendor advisory
  71. 2026-09-16 23:59 UTCEchelonGraph re-scored
  72. 2026-09-16 23:59 UTCVendor advisory
  73. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  74. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 10th percentile
  75. 2026-09-15 20:06 UTCEchelonGraph re-scored

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

Frequently asked(5)

What is CVE-2026-73563?
CVE-2026-73563 is a medium-severity vulnerability; its CVE record was 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 the CVE record for CVE-2026-73563 published?
The CVE record for CVE-2026-73563 was published on August 13, 2026. 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 October 15, 2026; the record at its source may have been updated since.
Is CVE-2026-73563 actively exploited?
CVE-2026-73563 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (6th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-73563?
CVE-2026-73563 has a CVSS v3 base score of 6.1 (NVD).
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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-73563

Explore →

Is Your Infrastructure Affected by CVE-2026-73563?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs