Vulnerability in Http4s Blaze
CVE-2026-73495
blaze is a Scala library for building asynchronous pipelines, with a focus on network IO. Prior to 0.23.18 and 1.0.0-M42, blaze-server can merge HTTP/1.1 chunked-body trailer fields into Request.headers. Because trailer fields are attacker…
Vulnerability class: HTTP Request Smuggling
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Http4s Blaze — versions < 0.23.18, >= 1.0.0-M1, < 1.0.0-M42
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-73495?
- CVE-2026-73495 is a high-severity vulnerability in Http4s Blaze, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 7.4/10. Published 2026-08-12.
- How severe is CVE-2026-73495?
- High severity. CVSS v3 base score is 7.4 out of 10.