# h3 (npm) vulnerabilities

Source: https://junglewise.ai/threats/technologies/h3  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Updated: 13 November 2026, 03:07 UTC. Rebuilt every hour.  
Data: https://junglewise.ai/threats/technologies/h3.json  
License: CC BY 4.0 with a link back

Junglewise Threat Intelligence has tracked 11 vulnerabilities in h3 (npm): 0 in the last 7 days and 6 in the last 90 days, 0 of them critical and 0 exploited in the wild. The most recent, H3 denial of service via unbounded chunked cookie count, was published on 6 September 2026. Nothing was published in the last eight weeks.

## Counts

- Last 7 days: 0
- Last 30 days: 0
- Last 90 days: 6
- All time: 11 (0 critical, 0 exploited in the wild)

## About h3 (npm)

JavaScript library for spatial indexing using hexagonal hierarchical geospatial indexing system.

## Latest h3 (npm) vulnerabilities

- [H3 denial of service via unbounded chunked cookie count](https://junglewise.ai/threats/duplicate-advisory-h3-unbounded-chunked-cookie-count-in-session-cleanup-11041bf9) (high, CVSS 7.5, published 6 Sep 2026)
- [CVE-2026-86253: h3 serveStatic path traversal via percent-encoded dot segments](https://junglewise.ai/threats/cve-2026-86253-h3-servestatic-path-traversal-via-percent-encoded-dot-segments) (medium, CVSS 5.9, published 6 Sep 2026)
- [CVE-2026-86252: h3 SSE event injection via unsanitized carriage return](https://junglewise.ai/threats/cve-2026-86252-h3-sse-event-injection-via-unsanitized-carriage-return) (medium, CVSS 5.3, published 6 Sep 2026)
- [CVE-2026-86251: h3 serveStatic path traversal via double-encoded dot segments](https://junglewise.ai/threats/cve-2026-86251-h3-servestatic-path-traversal-via-double-encoded-dot-segments) (medium, CVSS 5.9, published 6 Sep 2026)
- [CVE-2026-86250: H3: Unbounded Chunked Cookie Count in Session Cleanup Loop may Lead to Denial of Service](https://junglewise.ai/threats/cve-2026-86250-h3-unbounded-chunked-cookie-denial-of-service) (high, CVSS 7.5, published 6 Sep 2026)
- [CVE-2026-86205: H3 open redirect via protocol-relative path in redirectBack()](https://junglewise.ai/threats/cve-2026-86205-h3-open-redirect-via-protocol-relative-path-in-redirectback) (medium, CVSS 5.4, published 6 Sep 2026)
- [CVE-2026-33490: h3 missing path segment boundary check in mount()](https://junglewise.ai/threats/cve-2026-33490-h3js-h3-incorrect-path-validation-in-mount-method) (low, CVSS 3.1, published 20 Mar 2026)
- [CVE-2026-33131: h3 middleware bypass via Host header spoofing](https://junglewise.ai/threats/cve-2026-33131-h3js-h3-middleware-bypass-via-host-header-spoofing) (low, CVSS 3.1, published 18 Mar 2026)
- [CVE-2026-33129: h3 timing side-channel in basic auth validation](https://junglewise.ai/threats/cve-2026-33129-h3js-h3-timing-side-channel-in-requirebasicauth) (low, CVSS 3.1, published 18 Mar 2026)
- [CVE-2026-33128: h3 Server-Sent Events injection via unsanitized newlines](https://junglewise.ai/threats/cve-2026-33128-h3js-h3-server-sent-events-injection-in-createeventstream) (low, CVSS 3.1, published 18 Mar 2026)
- [CVE-2026-23527: h3js h3 HTTP request smuggling in readRawBody](https://junglewise.ai/threats/cve-2026-23527-h3js-h3-http-request-smuggling-in-readrawbody) (high, CVSS 8.9, published 15 Jan 2026)

## Most severe h3 (npm) vulnerabilities

- [CVE-2026-23527: h3js h3 HTTP request smuggling in readRawBody](https://junglewise.ai/threats/cve-2026-23527-h3js-h3-http-request-smuggling-in-readrawbody) (high, CVSS 8.9, published 15 Jan 2026)
- [CVE-2026-86250: H3: Unbounded Chunked Cookie Count in Session Cleanup Loop may Lead to Denial of Service](https://junglewise.ai/threats/cve-2026-86250-h3-unbounded-chunked-cookie-denial-of-service) (high, CVSS 7.5, published 6 Sep 2026)
- [H3 denial of service via unbounded chunked cookie count](https://junglewise.ai/threats/duplicate-advisory-h3-unbounded-chunked-cookie-count-in-session-cleanup-11041bf9) (high, CVSS 7.5, published 6 Sep 2026)
- [CVE-2026-86253: h3 serveStatic path traversal via percent-encoded dot segments](https://junglewise.ai/threats/cve-2026-86253-h3-servestatic-path-traversal-via-percent-encoded-dot-segments) (medium, CVSS 5.9, published 6 Sep 2026)
- [CVE-2026-86251: h3 serveStatic path traversal via double-encoded dot segments](https://junglewise.ai/threats/cve-2026-86251-h3-servestatic-path-traversal-via-double-encoded-dot-segments) (medium, CVSS 5.9, published 6 Sep 2026)
- [CVE-2026-86205: H3 open redirect via protocol-relative path in redirectBack()](https://junglewise.ai/threats/cve-2026-86205-h3-open-redirect-via-protocol-relative-path-in-redirectback) (medium, CVSS 5.4, published 6 Sep 2026)
- [CVE-2026-86252: h3 SSE event injection via unsanitized carriage return](https://junglewise.ai/threats/cve-2026-86252-h3-sse-event-injection-via-unsanitized-carriage-return) (medium, CVSS 5.3, published 6 Sep 2026)
- [CVE-2026-33128: h3 Server-Sent Events injection via unsanitized newlines](https://junglewise.ai/threats/cve-2026-33128-h3js-h3-server-sent-events-injection-in-createeventstream) (low, CVSS 3.1, published 18 Mar 2026)
- [CVE-2026-33129: h3 timing side-channel in basic auth validation](https://junglewise.ai/threats/cve-2026-33129-h3js-h3-timing-side-channel-in-requirebasicauth) (low, CVSS 3.1, published 18 Mar 2026)
- [CVE-2026-33131: h3 middleware bypass via Host header spoofing](https://junglewise.ai/threats/cve-2026-33131-h3js-h3-middleware-bypass-via-host-header-spoofing) (low, CVSS 3.1, published 18 Mar 2026)

## Vulnerabilities per week

Nothing was published in the last eight weeks.

| Week of | Vulns | Critical | Exploited |
| --- | --- | --- | --- |
| 17 Aug 2026 | 0 | 0 | 0 |
| 24 Aug 2026 | 0 | 0 | 0 |
| 31 Aug 2026 | 6 | 0 | 0 |
| 7 Sep 2026 | 0 | 0 | 0 |
| 14 Sep 2026 | 0 | 0 | 0 |
| 21 Sep 2026 | 0 | 0 | 0 |
| 28 Sep 2026 | 0 | 0 | 0 |
| 5 Oct 2026 | 0 | 0 | 0 |
| 12 Oct 2026 | 0 | 0 | 0 |
| 19 Oct 2026 | 0 | 0 | 0 |
| 26 Oct 2026 | 0 | 0 | 0 |
| 2 Nov 2026 | 0 | 0 | 0 |
| 9 Nov 2026 | 0 | 0 | 0 |

## Other npm technologies

- [openclaw (npm)](https://junglewise.ai/threats/technologies/npm-openclaw): 214 vulnerabilities
- [flowise (npm)](https://junglewise.ai/threats/technologies/flowise): 133 vulnerabilities
- [parse-server (npm)](https://junglewise.ai/threats/technologies/parse-server): 117 vulnerabilities
- [vm2 (npm)](https://junglewise.ai/threats/technologies/vm2): 111 vulnerabilities
- [electron (npm)](https://junglewise.ai/threats/technologies/electron): 77 vulnerabilities
- [ghost (npm)](https://junglewise.ai/threats/technologies/ghost): 74 vulnerabilities
- [n8n (npm)](https://junglewise.ai/threats/technologies/npm-n8n): 64 vulnerabilities
- [hono (npm)](https://junglewise.ai/threats/technologies/hono): 62 vulnerabilities
- [directus (npm)](https://junglewise.ai/threats/technologies/directus): 61 vulnerabilities
- [nocodb (npm)](https://junglewise.ai/threats/technologies/nocodb): 54 vulnerabilities
- [undici (npm)](https://junglewise.ai/threats/technologies/undici): 53 vulnerabilities
- [@budibase/server (npm)](https://junglewise.ai/threats/technologies/budibase-server): 42 vulnerabilities

## Sources

NVD, GitHub Security Advisories, OSV, the CISA Known Exploited Vulnerabilities catalog, FIRST EPSS and vendor advisories. Rebuilt every hour. Cite as: Junglewise Threat Intelligence, "h3 (npm) vulnerabilities", https://junglewise.ai/threats/technologies/h3, 13 November 2026.