CVE-2026-97032: Go Standard Library Net/http

EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Go Standard Library Net/http: before 1.26.9 (fixed in 1.26.9)
• Go Standard Library net/http/internal/http2: from 1.27.0-0, before 1.27.2 (fixed in 1.27.2)
• Golang.org/x/net golang.org/x/net/http2: before 0.60.0 (fixed in 0.60.0)

Published 2026-10-08. Last modified 2026-10-09.