HTTP/2 server crash due to HPACK encoder race in net/http
At a glance
Severity
HIGH 7.5
EPSS
EPSS 0.49 % · percentile 42 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Go
NVD status
Awaiting Analysis
Description
HTTP/2 servers could end up crashing due to inadvertently modifying its HPACK encoder concurrently. This happens because the server modifies the HPACK encoder from two goroutines without synchronization: one uses the encoder to encode a HEADERS frame as part of a response sent to a client and the other modifies the encoder's table size when handling a SETTINGS frame containing SETTINGS_HEADER_TABLE_SIZE that a client sends. A malicious client can repeatedly send a request while changing the header table size to crash the server.
