CVE-2026-33129 PUBLISHED

h3 has an observable timing discrepancy in basic auth utils

Assigner: GitHub_M
Reserved: 17.03.2026 Published: 20.03.2026 Updated: 20.03.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
CVSS Score: 5.9

Product Status

Vendor h3js
Product h3
Versions
  • Version >= 2.0.1-beta.0, < 2.0.1-rc.9 is affected

References

Problem Types

  • CWE-208: Observable Timing Discrepancy CWE