CVE-2026-84363

MEDIUMPre-NVD 5.95.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 72% 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
5.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.9Exploit: 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, Hono's query helpers treat a question mark after a literal hash fragment as the start of a query string, so the application can read request parameters that browsers, new URL(), reverse proxies, filtering rules, parameter allow and deny lists, access logging, request validation, and other middleware do not observe. The Cache Middleware removes the fragment when building its cache key, allowing a response influenced by parameters inside the fragment to be stored under a key that omits those parameters and later served to other users. This can bypass filtering and auditing, poison cached responses, and enable stored cross-site scripting when an affected parameter is reflected into cached HTML without escaping. Exploitation requires a runtime and intermediary path that passes a literal hash character through to the request URL; Cloudflare Workers and intermediaries that strip fragments are not affected. This issue is fixed in version 4.13.5.

CVSS v3
5.9
EG Score
5.9(medium)
EG Risk
27(Track)
EG Risk 27/100SSVC: 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
Severity59% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
28%
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 9c28d724c5a7 (honojs/hono)

Patch available: honojs/hono v4.13.5 (contains commit 9c28d724c5a7)

https://github.com/honojs/hono/commit/9c28d724c5a7fb086ebaa812fdc1ad6e957c63bc
github Patch Available

Query parser reads parameters after the URL fragment, causing cache-key and proxy interpretation differentials · Advisory · honojs/hono · GitHub

https://github.com/honojs/hono/security/advisories/GHSA-crvj-82cr-hjcx

Vendor Advisories for CVE-2026-84363(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 / 34× 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 07:46 UTCEG score recompute
  2. 2026-09-18 19:28 UTCEPSS rescore
  3. 2026-09-18 09:04 UTCEG score recompute
  4. 2026-09-17 19:32 UTCEPSS rescore
  5. 2026-09-17 10:25 UTCEG score recompute
  6. 2026-09-16 14:09 UTCEPSS rescore
  7. 2026-09-16 11:45 UTCEG score recompute
  8. 2026-09-16 05:15 UTCEPSS rescore
  9. 2026-09-15 13:06 UTCEG score recompute
  10. 2026-09-15 03:12 UTCEPSS rescore
  11. 2026-09-15 03:12 UTCEPSS rescore
  12. 2026-09-14 14:27 UTCEG score recompute
  13. 2026-09-12 17:09 UTCEG score recompute
  14. 2026-09-11 18:30 UTCEG score recompute
  15. 2026-09-11 14:53 UTCEPSS rescore
  16. 2026-09-11 14:53 UTCEPSS rescore
  17. 2026-09-10 19:50 UTCEG score recompute
  18. 2026-09-09 04:19 UTCEG score recompute
  19. 2026-09-08 22:01 UTCEPSS rescore
  20. 2026-09-08 05:39 UTCEG score recompute
  21. 2026-09-07 06:57 UTCEG score recompute
  22. 2026-09-06 13:48 UTCEPSS rescore
  23. 2026-09-06 08:19 UTCEG score recompute
  24. 2026-09-05 15:31 UTCEPSS rescore
  25. 2026-09-05 09:37 UTCEG score recompute
Show 9 more
  1. 2026-09-04 10:58 UTCEG score recompute
  2. 2026-09-04 05:07 UTCEPSS rescore
  3. 2026-09-03 12:16 UTCEG score recompute
  4. 2026-09-02 14:12 UTCEPSS rescore
  5. 2026-09-02 13:35 UTCEG score recompute
  6. 2026-09-02 12:36 UTCEG score recompute
  7. 2026-09-01 21:27 UTCEG score recompute
  8. 2026-09-01 20:34 UTCEG score recompute
  9. 2026-09-01 20:32 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-84363?
CVE-2026-84363 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, Hono's query helpers treat a question mark after a literal hash fragment as the start of a query string, so the application can read request parameters that browsers, new URL(), reverse proxies,…
When was CVE-2026-84363 disclosed?
CVE-2026-84363 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-2026-84363 actively exploited?
CVE-2026-84363 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 71.9% of all scored CVEs.
What is the CVSS score of CVE-2026-84363?
CVE-2026-84363 has a CVSS v3 base score of 5.9 (NVD).
How do I remediate CVE-2026-84363?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-84363, 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-2026-84363

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