CVE-2026-55473

MEDIUMPre-NVD 6.06.0
EchelonGraph scoreMEDIUM confidence

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

This medium-severity CVE scores 6.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4% (36th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source

Also known asEUVD-2026-84037 (ENISA EUVD)Source: ENISA EUVD

6.0EG
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: 0.4%CVSS: 6.0Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

HomeBox is a home inventory and organization system. Prior to 0.26.0, the default-on BlockBogonNets and BlockCloudMetadata notifier SSRF protections in backend/internal/sys/validate/notifier_url.go do not inspect IPv4 destinations embedded in the NAT64 prefixes 64:ff9b::/96 and 64:ff9b:1::/48. An authenticated user can submit a generic:// notifier through POST /v1/notifiers or POST /v1/notifiers/test, and on a Homebox instance that egresses through NAT64/DNS64, the gateway can translate an accepted IPv6 destination to cloud metadata, localhost, or another internal IPv4 host. The notifier test path returns delivery result information, and Shoutrrr propagates the response, providing feedback that can disclose retrieved metadata such as temporary credentials. Without NAT64 egress, the crafted IPv6 destination is not routable, but the guard still incorrectly classifies it as safe. This issue is fixed in version 0.26.0.

CVSS
6.0
EG Score
6.0MEDIUMmedium confidence
EG Risk
27
EG Risk 27/100

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)
Severity60% × 45%
Impact severity (EG Severity): CVSS 6.0 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.4% × 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
0.4%
EPSS %ILE
36th
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 (6.0): severity, escalated by confirmed exploitation. This CVE's 6.0 is its impact severity (EG Severity), not escalated.

EG Severity
6.0 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source
EG Likelihood
0.4% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-24). 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

September 21, 2026

Last Modified

September 29, 2026

Advisory Details (3)

Auto-updated Sep 21, 2026
Patch available. Sources: github, github_commit, github_release.
GitHub release Patch Available

v0.26.0

Patch available: sysadminsmedia/homebox v0.26.0

https://github.com/sysadminsmedia/homebox/releases/tag/v0.26.0
GitHub commit

commit 42c52f7f7566 (sysadminsmedia/homebox)

Fix landed in sysadminsmedia/homebox commit 42c52f7f7566 — awaiting tagged release

https://github.com/sysadminsmedia/homebox/commit/42c52f7f7566b7fbd8017352187af20f552a4471
GitHub advisoryMentions a patch (unverified)

Notifier SSRF guard misses NAT64 prefixes (64:ff9b::/96, 64:ff9b:1::/48) — generic:// URL reaches cloud metadata on NAT64 egress · Advisory · sysadminsmedia/homebox · GitHub

https://github.com/sysadminsmedia/homebox/security/advisories/GHSA-r9pf-rg22-655m

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 31× 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 → 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.

  1. 2026-11-13 16:53 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  2. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  3. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  5. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  6. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  7. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  8. 2026-11-06 16:38 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  9. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  10. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  11. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  12. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  13. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  14. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  15. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  16. 2026-10-30 10:55 UTCOSV refresh
  17. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  18. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  19. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  20. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  21. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  22. 2026-10-25 14:18 UTCEchelonGraph re-scored
  23. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  24. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  25. 2026-10-22 21:15 UTCEchelonGraph re-scored
Show 55 more
  1. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  2. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  3. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  4. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  5. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  6. 2026-10-18 03:30 UTCEchelonGraph re-scored
  7. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  8. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  9. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  10. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  11. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  12. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  13. 2026-10-12 15:55 UTCEchelonGraph re-scored
  14. 2026-10-11 19:39 UTCEchelonGraph re-scored
  15. 2026-10-11 16:54 UTCEchelonGraph re-scored
  16. 2026-10-11 14:17 UTCEchelonGraph re-scored
  17. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  18. 2026-10-11 10:34 UTCEchelonGraph re-scored
  19. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  20. 2026-10-10 08:47 UTCEchelonGraph re-scored
  21. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  22. 2026-10-09 07:05 UTCEchelonGraph re-scored
  23. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  24. 2026-10-08 05:22 UTCEchelonGraph re-scored
  25. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  26. 2026-10-07 03:40 UTCEchelonGraph re-scored
  27. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  28. 2026-10-06 01:49 UTCEchelonGraph re-scored
  29. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  30. 2026-10-05 00:06 UTCEchelonGraph re-scored
  31. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  32. 2026-10-03 22:23 UTCEchelonGraph re-scored
  33. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  34. 2026-10-02 20:40 UTCEchelonGraph re-scored
  35. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  36. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  37. 2026-09-30 17:09 UTCEchelonGraph re-scored
  38. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  39. 2026-09-29 15:25 UTCEchelonGraph re-scored
  40. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  41. 2026-09-29 14:27 UTCEchelonGraph re-scored
  42. 2026-09-29 03:27 UTCEchelonGraph re-scored
  43. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  44. 2026-09-28 01:45 UTCEchelonGraph re-scored
  45. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  46. 2026-09-26 23:58 UTCEchelonGraph re-scored
  47. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  48. 2026-09-24 20:21 UTCEchelonGraph re-scored
  49. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 32nd percentile
  50. 2026-09-23 18:39 UTCEchelonGraph re-scored
  51. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  52. 2026-09-22 20:09 UTCEchelonGraph re-scored
  53. 2026-09-21 18:27 UTCEchelonGraph re-scored
  54. 2026-09-21 17:55 UTCEchelonGraph re-scoredFirst assessed: 6.0 MEDIUM
  55. 2026-09-21 17:55 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-55473?
CVE-2026-55473 is a medium-severity vulnerability; its CVE record was published on September 21, 2026. HomeBox is a home inventory and organization system. Prior to 0.26.0, the default-on BlockBogonNets and BlockCloudMetadata notifier SSRF protections in backend/internal/sys/validate/notifier_url.go do not inspect IPv4 destinations embedded in the NAT64 prefixes 64:ff9b::/96 and 64:ff9b:1::/48. An…
When was the CVE record for CVE-2026-55473 published?
The CVE record for CVE-2026-55473 was published on September 21, 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 September 29, 2026; the record at its source may have been updated since.
Is CVE-2026-55473 actively exploited?
CVE-2026-55473 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55473?
CVE-2026-55473 has a CVSS base score of 6.0 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55473?
A fix for CVE-2026-55473 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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