Medium 5.9Published Mar 20, 2026

CVE-2026-33129H3 is a minimal H(TTP) framework.

Updated under an hour ago (2026-10-19 07:50 UTC)

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It affects h3. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for h3

Exploited in the last 30 days

H3 is a minimal H(TTP) framework. Versions 2.0.1-beta.0 through 2.0.0-rc.8 contain a Timing Side-Channel vulnerability in the requireBasicAuth function due to the use of unsafe string comparison (!==). This allows an attacker to deduce the valid password character-by-character by measuring the server's response time, effectively bypassing password complexity protections. This issue is fixed in version 2.0.1-rc.9.

CVSS: 5.9 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness (CWE): CWE-208
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jun 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

h3 h3 h3:h3	2.0.0; 2.0.1; 2.0.1; 2.0.1; 2.0.1; 2.0.1; 2.0.1; 2.0.1; and 1 more ranges	NVD

References

https://github.com/h3js/h3/pull/1283issue-tracking
https://github.com/h3js/h3/releases/tag/v2.0.1-rc.9patch
https://github.com/h3js/h3/security/advisories/GHSA-26f5-8h2x-34xhexploit, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.