CVE-2026-55513

MEDIUMPre-NVD 5.45.4
EchelonGraph scoreMEDIUM confidence

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

Score 5.4 from GitHub Security Advisory (severity: MODERATE) published 2026-07-14. A secondary CVSS source baseline 5.4; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-71719 (ENISA EUVD) · GHSA-g4x6-jcvr-9m3g (GitHub Security Advisories) · GO-2026-5987 (OSV.dev)Source: ENISA EUVD

5.4EG
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: 0.3%CVSS: 5.4Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. From version 0.3.0 to before version 0.5.0, the nebula-mgmt Web UI host-creation path ignores both the server-wide enrollment_token_ttl security setting and per-network network_config.enrollment_token_ttl overrides. API host creation and token-regeneration paths use the configured TTL resolver, but POST /ui/hosts hardcodes now.Add(24 * time.Hour) for newly minted agent enrollment tokens. In deployments that intentionally reduce enrollment-token lifetime, any authenticated operator who can create a host through the Web UI can still mint a bearer enrollment token valid for about 24 hours. This issue has been patched in version 0.5.0.

CVSS v3
5.4
EG Score
5.4MEDIUMmedium confidence
EG Risk
40
EG Risk 40/100

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)
Severity54% × 45%
Impact severity (EG Severity): CVSS 5.4 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.
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
0.3%
EPSS %ILE
25th
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 (5.4): severity, escalated by confirmed exploitation. This CVE's 5.4 is its impact severity (EG Severity), not escalated.

EG Severity
5.4 MEDIUMCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.3% 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 14, 2026

Last Modified

September 8, 2026

Advisory Details (3)

Auto-updated Sep 4, 2026
Patch available. Sources: github, github_commit, github_release.
GitHub release Patch Available

v0.5.0

Patch available: forgekeep/nebula-mesh v0.5.0

https://github.com/forgekeep/nebula-mesh/releases/tag/v0.5.0
GitHub commit

commit 514006029e09 (forgekeep/nebula-mesh)

Fix landed in forgekeep/nebula-mesh commit 514006029e09 — awaiting tagged release

https://github.com/forgekeep/nebula-mesh/commit/514006029e09f1991122b86a80e7b25970bcfa98
GitHub advisoryMentions a patch (unverified)

Web UI host creation ignores configured enrollment token TTL and mints 24-hour bearer enrollment tokens · Advisory · forgekeep/nebula-mesh · GitHub

https://github.com/forgekeep/nebula-mesh/security/advisories/GHSA-g4x6-jcvr-9m3g

Vendor Advisories for CVE-2026-55513(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/forgekeep/nebula-mesh @ 0.5.0 (fixes >= 0.3.0, < 0.5.0)—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

(2 across 1 ecosystem)
Go(2)
PackageVulnerable rangeFix by version rangeDependents
github.com/forgekeep/nebula-mesh—
  • 0.3.0 up to 0.5.0: fixed in 0.5.0
  • 0.4.0 up to 0.5.0: fixed in 0.5.0
—
github.com/juev/nebula-mesh—
  • 0.3.0 on: no fix on record
—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 40× 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.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  2. 2026-11-01 07:43 UTCGHSA enrichmentGHSA-g4x6-jcvr-9m3g · GitHub severity MODERATE · GitHub CVSS 5.4
  3. 2026-11-01 07:43 UTCEG score recompute
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.3% · 25th percentile
  5. 2026-10-30 16:34 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  6. 2026-10-30 10:55 UTCOSV refresh
  7. 2026-10-29 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  8. 2026-10-28 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  9. 2026-10-27 16:32 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  10. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  11. 2026-10-25 16:33 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  12. 2026-10-25 14:18 UTCEG score recompute
  13. 2026-10-24 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  14. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  15. 2026-10-22 21:15 UTCEG score recompute
  16. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  17. 2026-10-21 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  18. 2026-10-20 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  19. 2026-10-19 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  20. 2026-10-18 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  21. 2026-10-18 03:30 UTCEG score recompute
  22. 2026-10-17 16:34 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  23. 2026-10-16 16:42 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  24. 2026-10-15 16:32 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  25. 2026-10-14 16:33 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
Show 52 more
  1. 2026-10-13 16:34 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  2. 2026-10-12 16:34 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  3. 2026-10-12 15:55 UTCEG score recompute
  4. 2026-10-11 19:39 UTCEG score recompute
  5. 2026-10-11 16:54 UTCEG score recompute
  6. 2026-10-11 14:17 UTCEG score recompute
  7. 2026-10-11 13:49 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  8. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.3% · 23rd percentile
  9. 2026-10-09 20:07 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  10. 2026-10-08 17:12 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  11. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  12. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  13. 2026-10-05 17:43 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  14. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  15. 2026-10-03 14:26 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  16. 2026-10-02 17:56 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  17. 2026-10-01 19:50 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  18. 2026-10-01 12:50 UTCEG score recompute
  19. 2026-09-30 15:03 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  20. 2026-09-29 15:22 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  21. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  22. 2026-09-28 08:51 UTCEG score recompute
  23. 2026-09-27 13:48 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  24. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  25. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.3% · 22nd percentile
  26. 2026-09-24 08:58 UTCEG score recompute
  27. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  28. 2026-09-23 03:26 UTCEG score recompute
  29. 2026-09-20 20:16 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  30. 2026-09-18 19:28 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  31. 2026-09-18 04:49 UTCEG score recompute
  32. 2026-09-17 19:31 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  33. 2026-09-16 14:08 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  34. 2026-09-16 05:15 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  35. 2026-09-15 03:11 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  36. 2026-09-14 08:36 UTCEG score recompute
  37. 2026-09-13 16:47 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  38. 2026-09-13 07:29 UTCEG score recompute
  39. 2026-09-11 21:52 UTCEG score recompute
  40. 2026-09-11 14:53 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  41. 2026-09-10 09:35 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  42. 2026-09-08 22:01 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  43. 2026-09-08 20:24 UTCEG score recompute
  44. 2026-09-08 01:04 UTCEG score recompute
  45. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  46. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 8th percentile
  47. 2026-09-05 21:38 UTCEG score recompute
  48. 2026-09-04 20:30 UTCEG score recompute
  49. 2026-07-30 16:13 UTCEG score recompute
  50. 2026-07-26 11:41 UTCEG score recompute
  51. 2026-07-23 03:20 UTCEG score recompute
  52. 2026-07-14 20:56 UTCEG score recompute

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Frequently asked(5)

What is CVE-2026-55513?
CVE-2026-55513 is a medium-severity vulnerability; its CVE record was published on July 14, 2026. nebula-mesh is a self-hosted control plane for Slack Nebula mesh VPN. From version 0.3.0 to before version 0.5.0, the nebula-mgmt Web UI host-creation path ignores both the server-wide enrollment_token_ttl security setting and per-network network_config.enrollment_token_ttl overrides. API host…
When was the CVE record for CVE-2026-55513 published?
The CVE record for CVE-2026-55513 was published on July 14, 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 8, 2026; the record at its source may have been updated since.
Is CVE-2026-55513 actively exploited?
CVE-2026-55513 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (25th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-55513?
CVE-2026-55513 has a CVSS base score of 5.4 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-55513?
A fix for CVE-2026-55513 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-55513 are linked in the Vendor Advisories panel on this page.

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