Inconsistent interpretation of HTTP requests in Apache bRPC - CVE-2026-86146
Published: October 23, 2026
Vulnerability identifier: #VU157366
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-86146
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to smuggle HTTP requests, inject headers, or desynchronize HTTP responses.
The vulnerability exists due to inconsistent HTTP message interpretation in Apache bRPC's bundled HTTP/1.1 parser when its handling of malformed framing headers, chunked trailers, or Transfer-Encoding lists differs from an intermediary's parsing. A remote attacker can send ambiguous headers such as Content-Length : 5 or Content-Length: 1 3, or place Authorization or X-Forwarded-For fields in chunked trailers, to create framing discrepancies or introduce headers that the front-end did not inspect.
Affected software
Apache bRPC
How to mitigate CVE-2026-86146
Install security update from vendor's website.
Apache bRPC - update to 1.18.0