CVE-2026-84364

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 67% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.13.5, when parseBody() expands dot-separated form field names into nested objects with dot-notation parsing enabled, it does not limit the nesting depth or the total number of intermediate objects created. Empty segments are preserved, so one deeply dotted field name can encode one nesting level per byte, while a large number of shallowly dotted fields can create the same amplification across a request. A request body within a normal size limit can therefore allocate an object graph far larger than the request after the body has already been accepted. An unauthenticated attacker who can reach an affected endpoint can send concurrent requests that exhaust the JavaScript heap, terminate the server process, and leave the service unavailable until restart. Dot-notation parsing is not enabled by default, and applications using the default behavior are not affected. This issue is fixed in version 4.13.5.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
33%
KEV
Not listed

Published

September 1, 2026

Last Modified

September 9, 2026

Advisory Details (3)

Auto-updated Sep 1, 2026
Patch available. Sources: github_release, github, github_commit.
github_release Patch Available

v4.13.5

Patch available: honojs/hono v4.13.5

https://github.com/honojs/hono/releases/tag/v4.13.5
github_commit Patch Available

commit 531e9c5a3ae0 (honojs/hono)

Patch available: honojs/hono v4.13.5 (contains commit 531e9c5a3ae0)

https://github.com/honojs/hono/commit/531e9c5a3ae058d10de33f643055bd4009a87178
github Patch Available

Unbounded dot-notation nesting in `parseBody()` can cause memory exhaustion · Advisory · honojs/hono · GitHub

https://github.com/honojs/hono/security/advisories/GHSA-g6gw-c38x-mqfc

Vendor Advisories for CVE-2026-84364(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
hono—4.13.5—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 13× in last 7d / 32× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. 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. Most recent first.

  1. 2026-09-19 11:56 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 10:21 UTCEG score recompute
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-17 08:46 UTCEG score recompute
  6. 2026-09-16 14:09 UTCEPSS rescore
  7. 2026-09-16 07:11 UTCEG score recompute
  8. 2026-09-16 05:15 UTCEPSS rescore
  9. 2026-09-15 05:35 UTCEG score recompute
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-15 03:12 UTCEPSS rescore
  12. 2026-09-14 03:29 UTCEG score recompute
  13. 2026-09-13 01:55 UTCEG score recompute
  14. 2026-09-12 00:20 UTCEG score recompute
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-11 14:53 UTCEPSS rescore
  17. 2026-09-10 22:45 UTCEG score recompute
  18. 2026-09-09 02:19 UTCEG score recompute
  19. 2026-09-08 22:01 UTCEPSS rescore
  20. 2026-09-08 00:41 UTCEG score recompute
  21. 2026-09-06 23:06 UTCEG score recompute
  22. 2026-09-06 13:48 UTCEPSS rescore
  23. 2026-09-05 21:23 UTCEG score recompute
  24. 2026-09-05 15:31 UTCEPSS rescore
  25. 2026-09-04 19:48 UTCEG score recompute
Show 7 more
  1. 2026-09-04 05:07 UTCEPSS rescore
  2. 2026-09-02 16:38 UTCEG score recompute
  3. 2026-09-02 15:53 UTCEG score recompute
  4. 2026-09-02 14:12 UTCEPSS rescore
  5. 2026-09-01 21:27 UTCEG score recompute
  6. 2026-09-01 20:34 UTCEG score recompute
  7. 2026-09-01 20:32 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84364?
CVE-2026-84364 is a medium vulnerability published on September 1, 2026. Hono is a Web application framework that provides support for any JavaScript runtime. Prior to 4.13.5, when parseBody() expands dot-separated form field names into nested objects with dot-notation parsing enabled, it does not limit the nesting depth or the total number of intermediate objects…
When was CVE-2026-84364 disclosed?
CVE-2026-84364 was first published in the National Vulnerability Database on September 1, 2026, with the most recent update on September 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-84364 actively exploited?
CVE-2026-84364 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 67.2% of all scored CVEs.
What is the CVSS score of CVE-2026-84364?
CVE-2026-84364 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-84364?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84364, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-84364

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