CVE-2026-10725: Crux protocol::http2

High severity, CVSS 7.5. EPSS: 0.4% chance of exploitation in the next 30 days.

Protocol::HTTP2 versions before 1.13 for Perl is vulnerable to a HTTP/2 Bomb. Protocol::HTTP2's inbound HPACK path has no header-list size limit, so a small HTTP/2 request can expand into large server memory (the "HTTP/2 bomb"). The headers_decode method materialises a full key+value copy per indexed reference with no running size check, and the stream_header_block_add method appends (since version 1.12) every CONTINUATION frame to the per-stream buffer unbounded. MAX_HEADER_LIST_SIZE (default 65536) is advertised in SETTINGS but never consulted on decode. It is absent from the decoder and from the :limits export tag.

Affected products

• Crux protocol::http2: before 1.13 (fixed in 1.13)

Published 2026-06-06. Last modified 2026-07-23.