CVE-2026-18500

HIGHPre-NVD 8.18.1
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.1 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (17th 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-2026-59757 (ENISA EUVD)Source: ENISA EUVD

8.1EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 8.1Exploit: None knownExposed services: Not assessed

The CVE record names the fixed release — apply it.

@fastify/jwt is a JSON Web Token plugin for Fastify. In versions before 10.2.2, a per-request verification key passed to request.jwtVerify({ key }) is silently overridden by the plugin's globally configured secret, because the option merge applies the global key last. Applications that use different keys for different authorization domains, for example separate user and admin keys, therefore accept a token signed with the global key on a route that explicitly requires another key. This lets an ordinary authenticated user cross a key-based trust boundary without knowing either secret. The issue is fixed in @fastify/jwt 10.2.2, where an explicit per-call key takes precedence over the global secret. Users should upgrade to 10.2.2.

CVSS v3
8.1
EG Score
8.1HIGHmedium 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)
Severity81% × 45%
Impact severity (EG Severity): CVSS 8.1 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.3% × 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 low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (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: The CVE record names the fixed release. Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
17th
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 (8.1): severity, escalated by confirmed exploitation. This CVE's 8.1 is its impact severity (EG Severity), not escalated.

EG Severity
8.1 HIGHCVSS-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
0.3% 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: 14 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).

The CVE record names the fixed release. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (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)14 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 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

August 15, 2026

Last Modified

September 4, 2026

Advisory Details (2)

Auto-updated Aug 15, 2026
Fix named in the CVE record. Sources: github.
Web page

Security Advisories | OpenJS Foundation CVE Numbering Authority

https://cna.openjsf.org/security-advisories.html
GitHub advisoryMentions a patch (unverified)

@fastify/jwt vulnerable to authorization bypass via global secret overriding the per-request key · Advisory · fastify/fastify-jwt · GitHub

https://github.com/fastify/fastify-jwt/security/advisories/GHSA-j4cx-787j-xjqg

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 8× in last 7d / 42× 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 121 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 21 oldest rows on record are not shown and were not checked, so the counts can still include repeats.

  1. 2026-11-01 16:34 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  2. 2026-10-31 21:54 UTCEG score recompute
  3. 2026-10-31 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  4. 2026-10-30 16:33 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  5. 2026-10-29 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  6. 2026-10-28 16:31 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  7. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  8. 2026-10-26 16:31 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  9. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.3% · 17th percentile
  10. 2026-10-25 14:45 UTCEG score recompute
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  12. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  13. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  14. 2026-10-22 16:34 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  15. 2026-10-21 16:32 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  16. 2026-10-20 16:32 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  17. 2026-10-19 16:31 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  18. 2026-10-18 16:31 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  19. 2026-10-18 03:58 UTCEG score recompute
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  21. 2026-10-17 16:33 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  22. 2026-10-16 16:40 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  23. 2026-10-15 16:31 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  24. 2026-10-14 16:32 UTCEPSS rescoreEPSS 0.3% · 16th percentile
  25. 2026-10-13 16:33 UTCEPSS rescoreEPSS 0.3% · 16th percentile
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  1. 2026-10-12 16:33 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  2. 2026-10-12 16:27 UTCEG score recompute
  3. 2026-10-11 20:07 UTCEG score recompute
  4. 2026-10-11 17:20 UTCEG score recompute
  5. 2026-10-11 14:52 UTCEG score recompute
  6. 2026-10-11 13:48 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  7. 2026-10-10 19:59 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  8. 2026-10-09 20:06 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  9. 2026-10-08 17:11 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  10. 2026-10-07 23:47 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  11. 2026-10-06 21:58 UTCEG score recompute
  12. 2026-10-06 15:17 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  13. 2026-10-06 09:08 UTCEG score recompute
  14. 2026-10-05 17:42 UTCEPSS rescoreEPSS 0.3% · 15th percentile
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  16. 2026-10-04 23:21 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  17. 2026-10-03 19:28 UTCEG score recompute
  18. 2026-10-03 14:25 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  19. 2026-10-02 01:58 UTCEG score recompute
  20. 2026-10-01 19:49 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  21. 2026-09-30 20:55 UTCEG score recompute
  22. 2026-09-30 15:02 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  23. 2026-09-29 15:20 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  24. 2026-09-28 23:35 UTCEG score recompute
  25. 2026-09-28 13:51 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  26. 2026-09-27 22:31 UTCEG score recompute
  27. 2026-09-27 13:47 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  28. 2026-09-27 08:23 UTCEG score recompute
  29. 2026-09-26 15:58 UTCEPSS rescoreEPSS 0.3% · 15th percentile
  30. 2026-09-24 16:23 UTCEG score recompute
  31. 2026-09-23 15:42 UTCEG score recompute
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  34. 2026-09-21 04:08 UTCEG score recompute
  35. 2026-09-19 16:32 UTCEG score recompute
  36. 2026-09-19 04:40 UTCEG score recompute
  37. 2026-09-18 19:27 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  38. 2026-09-18 03:42 UTCEG score recompute
  39. 2026-09-16 16:06 UTCEG score recompute
  40. 2026-09-16 14:07 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  41. 2026-09-16 05:14 UTCEPSS rescoreEPSS 0.2% · 5th percentile
  42. 2026-09-15 14:31 UTCEG score recompute
  43. 2026-09-14 02:54 UTCEG score recompute
  44. 2026-09-13 16:46 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  45. 2026-09-12 15:17 UTCEG score recompute
  46. 2026-09-12 15:00 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  47. 2026-09-11 15:32 UTCEG score recompute
  48. 2026-09-11 14:52 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  49. 2026-09-11 09:36 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  50. 2026-09-10 15:46 UTCEG score recompute
  51. 2026-09-10 09:34 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  52. 2026-09-09 03:50 UTCEG score recompute
  53. 2026-09-08 22:00 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  54. 2026-09-07 16:13 UTCEG score recompute
  55. 2026-09-07 16:01 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  56. 2026-09-07 01:08 UTCEG score recompute
  57. 2026-09-06 13:47 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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  60. 2026-09-04 05:06 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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  62. 2026-09-02 14:11 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  63. 2026-09-01 21:56 UTCEG score recompute
  64. 2026-09-01 13:53 UTCEPSS rescoreEPSS 0.2% · 4th percentile
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  67. 2026-08-30 19:46 UTCEG score recompute
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  73. 2026-08-27 19:27 UTCEG score recompute
  74. 2026-08-27 14:25 UTCEPSS rescoreEPSS 0.2% · 4th percentile
  75. 2026-08-26 18:28 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-18500?
CVE-2026-18500 is a high-severity vulnerability; its CVE record was published on August 15, 2026. @fastify/jwt is a JSON Web Token plugin for Fastify. In versions before 10.2.2, a per-request verification key passed to request.jwtVerify({ key }) is silently overridden by the plugin's globally configured secret, because the option merge applies the global key last. Applications that use…
When was the CVE record for CVE-2026-18500 published?
The CVE record for CVE-2026-18500 was published on August 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 4, 2026; the record at its source may have been updated since.
Is CVE-2026-18500 actively exploited?
CVE-2026-18500 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (17th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-18500?
CVE-2026-18500 has a CVSS base score of 8.1 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-18500?
The CVE record for CVE-2026-18500 names the fix: "Users should upgrade to 10.2.2."

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