Reachable assertion in Apache bRPC - CVE-2026-78048
Published: October 23, 2026
Vulnerability identifier: #VU157350
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-78048
CWE-ID: CWE-617
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service by aborting a bRPC server process.
The vulnerability exists due to a reachable assertion in Apache bRPC's HPACK decoder when dynamic-table capacity is calculated using a 34-byte minimum entry size although valid entries can occupy 33 bytes. A remote attacker can send a crafted header sequence that inserts 121 minimal entries into the default 4096-byte table to exhaust its 120 allocated slots and trigger CHECK(!_header_queue.full()), aborting the process.
Affected software
Apache bRPC
How to mitigate CVE-2026-78048
Install security update from vendor's website.
Apache bRPC - update to 1.18.0