CVE-2026-23527

HIGH

8.9

Description

H3 is a minimal H(TTP) framework built for high performance and portability. Prior to 1.15.5, there is a critical HTTP Request Smuggling vulnerability. readRawBody is doing a strict case-sensitive check for the Transfer-Encoding header. It explicitly looks for "chunked", but per the RFC, this header should be case-insensitive. This vulnerability is fixed in 1.15.5.

CVE Details

CVSS v3.1 Score8.9

SeverityHIGH

CVSS VectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L

Attack VectorNETWORK

ComplexityHIGH

Privileges RequiredNONE

User InteractionNONE

Published1/15/2026

Last Modified1/23/2026

Sourcenvd

Honeypot Sightings0

Affected Products

h3:h3

Weaknesses (CWE)

CWE-444

References

https://github.com/h3js/h3/commit/618ccf4f37b8b6148bea7f36040471af45bfb097(security-advisories@github.com)

https://github.com/h3js/h3/security/advisories/GHSA-mp2g-9vg9-f4cg(security-advisories@github.com)

IOC Correlations

No correlations recorded

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