CVE-2026-58196

MEDIUMPre-NVD 4.74.7
EchelonGraph scoreMEDIUM confidence

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

Score 4.7 from GitHub Security Advisory (severity: LOW) published 2026-07-15. A secondary CVSS source baseline 4.7; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Elevated

Also known asEUVD-2026-78818 (ENISA EUVD) · GHSA-pr64-jmmf-jp54 (GitHub Security Advisories) · GO-2026-6002 (OSV.dev)Source: ENISA EUVD

4.7EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (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: 0.4%CVSS: 4.7Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

ToolHive is a utility designed to simplify the deployment and management of Model Context Protocol (MCP) servers. Prior to 0.31.0, remote.Handler.Authenticate in pkg/auth/remote/handler.go invokes discovery.DetectAuthenticationFromServer in pkg/auth/discovery/discovery.go, whose host-side HTTP clients trust remote-server-controlled authentication discovery destinations, follow redirects without host or scheme restrictions, and do not consistently block private addresses. A malicious or compromised remote MCP server can place a resource_metadata URL in WWW-Authenticate for ParseWWWAuthenticate to extract, after which FetchResourceMetadata, OIDC issuer discovery, and well-known discovery can issue GET requests to link-local, RFC1918, or other internal services outside the server's container. The user connects to a server that the user intends to use, but the server controls the internal destination; this path does not depend on the separate NAT64 guard omission because the affected clients did not invoke IsPrivateIP, and it differs from the DCR resolver path that already refused redirects. The demonstrated primitive reaches internal-only HTTP services and reachability or error oracles, and can retrieve AWS metadata credentials where IMDSv1 accepts an unauthenticated GET, while IMDSv2 and GCP metadata prerequisites are not satisfied by the demonstrated request. This vulnerability is fixed in 0.31.0.

CVSS v3
4.7
EG Score
4.7MEDIUMmedium confidence
EG Risk
37
EG Risk 37/100

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)
Severity47% × 45%
Impact severity (EG Severity): CVSS 4.7 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.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation public PoC (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
37th
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 (4.7): severity, escalated by confirmed exploitation. This CVE's 4.7 is its impact severity (EG Severity), not escalated.

EG Severity
4.7 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.4% 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 low or medium mission impact; Track* at high (mission-essential systems).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 low or medium mission impact; Track* at high (mission-essential systems).

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

Exploitation public PoC (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

July 15, 2026

Last Modified

September 30, 2026

Advisory Details (3)

Auto-updated Sep 15, 2026
Patch available. Sources: github_release, github, github_commit.
GitHub release Patch Available

v0.31.0

Patch available: stacklok/toolhive v0.31.0

https://github.com/stacklok/toolhive/releases/tag/v0.31.0
GitHub commit

commit 4ea6afb9048d (stacklok/toolhive)

Fix landed in stacklok/toolhive commit 4ea6afb9048d — awaiting tagged release

https://github.com/stacklok/toolhive/commit/4ea6afb9048ddec1d56875fa9e0da36d65c15966
GitHub advisoryMentions a patch (unverified)

SSRF in remote MCP server authentication discovery (host-side, bypasses container isolation) · Advisory · stacklok/toolhive · GitHub

https://github.com/stacklok/toolhive/security/advisories/GHSA-pr64-jmmf-jp54

Vendor Advisories for CVE-2026-58196(1)

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

Patch Availability(1)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
gogithub.com/stacklok/toolhive @ 0.31.0 (fixes < 0.31.0)—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

(1 across 1 ecosystem)
Go(1)
PackageVulnerable rangeFix by version rangeDependents
github.com/stacklok/toolhive—
  • every version up to 0.31.0: fixed in 0.31.0
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 32× 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.

  1. 2026-11-13 16:53 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  2. 2026-11-12 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  3. 2026-11-11 16:40 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  4. 2026-11-10 16:44 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  5. 2026-11-09 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  6. 2026-11-08 16:40 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  7. 2026-11-07 16:39 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  8. 2026-11-06 16:38 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  9. 2026-11-05 16:38 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  10. 2026-11-04 16:36 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  11. 2026-11-03 16:48 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  12. 2026-11-02 16:45 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  13. 2026-11-01 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  14. 2026-11-01 07:42 UTCGHSA enrichmentGHSA-pr64-jmmf-jp54 · GitHub severity LOW · GitHub CVSS 4.7
  15. 2026-11-01 07:42 UTCEchelonGraph re-scored
  16. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  17. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  18. 2026-10-30 10:25 UTCOSV refresh
  19. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  20. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  21. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  22. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  23. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  24. 2026-10-25 14:16 UTCEchelonGraph re-scored
  25. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
Show 53 more
  1. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  2. 2026-10-22 21:01 UTCEchelonGraph re-scored
  3. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  4. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  5. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  6. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  7. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  8. 2026-10-18 03:28 UTCEchelonGraph re-scored
  9. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  10. 2026-10-16 16:43 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  11. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  12. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  13. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  14. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  15. 2026-10-12 15:53 UTCEchelonGraph re-scored
  16. 2026-10-11 19:36 UTCEchelonGraph re-scored
  17. 2026-10-11 16:52 UTCEchelonGraph re-scored
  18. 2026-10-11 14:14 UTCEchelonGraph re-scored
  19. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  20. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  21. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  22. 2026-10-08 17:13 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  23. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  24. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 35th percentile
  25. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  26. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  27. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  28. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  29. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  30. 2026-09-30 18:11 UTCEchelonGraph re-scored
  31. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  32. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  33. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  34. 2026-09-28 08:40 UTCEchelonGraph re-scored
  35. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  36. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  37. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 34th percentile
  38. 2026-09-24 08:45 UTCEchelonGraph re-scored
  39. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  40. 2026-09-23 03:12 UTCEchelonGraph re-scored
  41. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  42. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  43. 2026-09-18 04:42 UTCEchelonGraph re-scored
  44. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  45. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.4% · 31st percentile
  46. 2026-09-15 18:36 UTCEchelonGraph re-scored
  47. 2026-09-15 18:14 UTCEchelonGraph re-scored
  48. 2026-09-15 16:35 UTCEchelonGraph re-scored
  49. 2026-09-15 16:02 UTCMITRE cvelistV5severity → MEDIUM
  50. 2026-07-31 00:48 UTCEchelonGraph re-scored
  51. 2026-07-26 11:28 UTCEchelonGraph re-scored
  52. 2026-07-23 03:20 UTCEchelonGraph re-scored
  53. 2026-07-15 23:54 UTCEchelonGraph re-scored

Related CVEs(same product + same CWE)

Same product

2 shown

Go:github.com/stacklok/toolhive

Frequently asked(5)

What is CVE-2026-58196?
CVE-2026-58196 is a medium-severity vulnerability; its CVE record was published on July 15, 2026. ToolHive is a utility designed to simplify the deployment and management of Model Context Protocol (MCP) servers. Prior to 0.31.0, remote.Handler.Authenticate in pkg/auth/remote/handler.go invokes discovery.DetectAuthenticationFromServer in pkg/auth/discovery/discovery.go, whose host-side HTTP…
When was the CVE record for CVE-2026-58196 published?
The CVE record for CVE-2026-58196 was published on July 15, 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-2026-58196 actively exploited?
CVE-2026-58196 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (37th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-58196?
CVE-2026-58196 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-2026-58196?
A fix for CVE-2026-58196 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-58196 are linked in the Vendor Advisories panel on this page.

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