CVE-2026-54618

CRITICALPre-NVD 9.49.4
EchelonGraph scoreMEDIUM confidence

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

This critical-severity CVE scores 9.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5% (43rd 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
Elevated

Also known asEUVD-2026-82406 (ENISA EUVD)Source: ENISA EUVD

9.4EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 9.4Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

Obsidian Web MCP is a secure remote MCP server for Obsidian vaults. Prior to 0.2.0, /oauth/authorize issues an authorization code without a login, consent, or session check, and /oauth/token can exchange that code for the static VAULT_MCP_TOKEN without authenticating a client. An unauthenticated remote caller who can reach the intended tunnel deployment can therefore call /mcp and use vault_read, vault_write, vault_search, vault_list, vault_move, and vault_delete against the entire vault. Optional PKCE does not prevent an attacker-initiated flow, and unauthenticated /oauth/register also exposes a client_credentials path by returning the configured VAULT_OAUTH_CLIENT_SECRET. This issue is fixed in version 0.2.0.

CVSS v3
9.4
EG Score
9.4CRITICALmedium confidence
EG Risk
73
EG Risk 73/100

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)
Severity94% × 45%
Impact severity (EG Severity): CVSS 9.4 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low, Track* at medium and Attend at high mission impact.
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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 at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
43rd
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 (9.4): severity, escalated by confirmed exploitation. This CVE's 9.4 is its impact severity (EG Severity), not escalated.

EG Severity
9.4 CRITICALCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-11-03). 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, Track* at medium and Attend at high mission impact.CISA BOD 26-04: 3 days if the affected system is publicly exposed; 60 days 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, Track* at medium and Attend at high mission impact.

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

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact total (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)3 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact total (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 17, 2026

Last Modified

September 30, 2026

Advisory Details (4)

Auto-updated Oct 2, 2026
Patch available. Sources: github_commit, github_pr, github_release, github.
GitHub advisoryMentions a patch (unverified)

Unauthenticated vault access: /oauth/authorize auto-approves without authenticating the user · Advisory · jimprosser/obsidian-web-mcp · GitHub

https://github.com/jimprosser/obsidian-web-mcp/security/advisories/GHSA-hwhg-mrjc-8g43
GitHub release Patch Available

v0.2.0 — security fix (#8, #29)

Patch available: jimprosser/obsidian-web-mcp v0.2.0

https://github.com/jimprosser/obsidian-web-mcp/releases/tag/v0.2.0
GitHub pull request Patch Available

Fix critical auth bypass: authenticate before issuing OAuth tokens (#8, #29)

Patch available: jimprosser/obsidian-web-mcp v0.2.0 (PR #30 merged 2026-06-07)

https://github.com/jimprosser/obsidian-web-mcp/pull/30
GitHub commit Patch Available

commit e4924f096ee7 (jimprosser/obsidian-web-mcp)

Patch available: jimprosser/obsidian-web-mcp v0.2.0 (contains commit e4924f096ee7)

https://github.com/jimprosser/obsidian-web-mcp/commit/e4924f096ee7494a7999d6c0cceca9be08e48eef

Weakness Classification(3)

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

Data Freshness Timeline

(refreshed 14× in last 7d / 63× 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 it from the CNA feed. 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). Most recent first.

Showing the most recent 100 of 101 refreshes 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 1 oldest row on record is not shown and was not checked, so the counts can still include repeats.

  1. 2026-11-04 16:35 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  2. 2026-11-04 05:36 UTCEG score recompute
  3. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  4. 2026-11-03 05:56 UTCEG score recompute
  5. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
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  7. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  8. 2026-11-01 06:37 UTCEG score recompute
  9. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
  10. 2026-10-31 06:57 UTCEG score recompute
  11. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
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  13. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
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  15. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
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  17. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.5% · 43rd percentile
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  19. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
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  21. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
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  24. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  25. 2026-10-24 07:05 UTCEG score recompute
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  1. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  2. 2026-10-23 07:23 UTCEG score recompute
  3. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  4. 2026-10-22 07:42 UTCEG score recompute
  5. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  6. 2026-10-21 08:01 UTCEG score recompute
  7. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  8. 2026-10-20 08:21 UTCEG score recompute
  9. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.5% · 42nd percentile
  10. 2026-10-19 08:40 UTCEG score recompute
  11. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
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  13. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  14. 2026-10-17 07:02 UTCEG score recompute
  15. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.5% · 41st percentile
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  17. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  18. 2026-10-15 06:18 UTCEG score recompute
  19. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  20. 2026-10-14 01:58 UTCEG score recompute
  21. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  22. 2026-10-12 22:15 UTCEG score recompute
  23. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  24. 2026-10-12 15:56 UTCEG score recompute
  25. 2026-10-11 19:39 UTCEG score recompute
  26. 2026-10-11 16:54 UTCEG score recompute
  27. 2026-10-11 14:17 UTCEG score recompute
  28. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  29. 2026-10-10 20:52 UTCEG score recompute
  30. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  31. 2026-10-09 21:49 UTCEG score recompute
  32. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.5% · 41st percentile
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  35. 2026-10-08 01:47 UTCEG score recompute
  36. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.5% · 41st percentile
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  38. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.5% · 41st percentile
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  42. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.5% · 41st percentile
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  44. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.5% · 41st percentile
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  46. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.5% · 41st percentile
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  48. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  49. 2026-09-30 16:52 UTCEG score recompute
  50. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  51. 2026-09-29 18:21 UTCEG score recompute
  52. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  53. 2026-09-28 22:14 UTCEG score recompute
  54. 2026-09-28 14:07 UTCEG score recompute
  55. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  56. 2026-09-27 15:15 UTCEG score recompute
  57. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  58. 2026-09-26 16:17 UTCEG score recompute
  59. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.5% · 40th percentile
  60. 2026-09-26 00:46 UTCEG score recompute
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  64. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.6% · 45th percentile
  65. 2026-09-23 21:31 UTCEG score recompute
  66. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  67. 2026-09-22 15:02 UTCEG score recompute
  68. 2026-09-21 23:46 UTCEG score recompute
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  70. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  71. 2026-09-19 18:20 UTCEG score recompute
  72. 2026-09-18 23:06 UTCEG score recompute
  73. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 33rd percentile
  74. 2026-09-17 20:18 UTCEG score recompute
  75. 2026-09-17 19:51 UTCEG score recomputeFirst assessed: 9.4 CRITICAL

Frequently asked(5)

What is CVE-2026-54618?
CVE-2026-54618 is a critical-severity vulnerability; its CVE record was published on September 17, 2026. Obsidian Web MCP is a secure remote MCP server for Obsidian vaults. Prior to 0.2.0, /oauth/authorize issues an authorization code without a login, consent, or session check, and /oauth/token can exchange that code for the static VAULT_MCP_TOKEN without authenticating a client. An unauthenticated…
When was the CVE record for CVE-2026-54618 published?
The CVE record for CVE-2026-54618 was published on September 17, 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 30, 2026; the record at its source may have been updated since.
Is CVE-2026-54618 actively exploited?
CVE-2026-54618 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (43rd percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-54618?
CVE-2026-54618 has a CVSS base score of 9.4 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-54618?
A fix for CVE-2026-54618 is available: update to the fixed version the vendor names in its advisory.

Dependency Blast Radius

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