CVE-2026-23527
8.9 · HIGHOverview
CVE-2026-23527 is a high-severity vulnerability affecting h3 h3. It was published on January 15, 2026 and has a CVSS 3.1 base score of 8.9 (HIGH).
This vulnerability has a CVSS 3.1 base score of 8.9, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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.
Remediation
Check the references section for vendor advisories and patches from h3. Update h3 to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| h3 | h3 | >= 0, < 1.15.5 | Affected |
Frequently Asked Questions
What is CVE-2026-23527?
CVE-2026-23527 is a high-severity vulnerability affecting h3 h3. It was published on January 15, 2026 and has a CVSS 3.1 base score of 8.9 (HIGH).
How severe is CVE-2026-23527?
This vulnerability has a CVSS 3.1 base score of 8.9, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-23527?
Check the references section for vendor advisories and patches from h3. Update h3 to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-23527?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-23527 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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