CVE-2026-10725

Protocol::HTTP2 versions before 1.13 for Perl is vulnerable to a HTTP/2 Bomb

Published Jun 6, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Workaround

Apply the patch.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Crux protocol\
CPEs cpe:2.3:a:crux:protocol\:\:http2:*:*:*:*:*:perl:*:*
Vendors & Products Crux protocol\
Type Values Removed Values Added
Description Protocol::HTTP2 versions through 1.12 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. 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.
Title Protocol::HTTP2 versions through 1.12 for Perl is vulnerable to a HTTP/2 Bomb Protocol::HTTP2 versions before 1.13 for Perl is vulnerable to a HTTP/2 Bomb
References
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Crux
Crux protocol::http2
Vendors & Products Crux
Crux protocol::http2
Type Values Removed Values Added
Description Protocol::HTTP2 versions through 1.12 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.
Title Protocol::HTTP2 versions through 1.12 for Perl is vulnerable to a HTTP/2 Bomb
Weaknesses CWE-409
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
CPANSec
Published
Updated
Jun 9, 2026, 7:20 AM
Reserved
Jun 3, 2026, 9:18 AM
Status
Analyzed
Published
Jun 6, 2026, 10:16 AM
Modified
Jul 23, 2026, 7:10 AM