CPANSA-Protocol-HTTP2-2026-10725: Protocol-HTTP2 vulnerability

Publisher giterlizzi Document category csaf_security_advisory
Initial release date 2026-06-06T00:00:00 Engine CSAF Perl Toolkit 0.26
Current release date 2026-06-06T00:00:00 Build Date
Current version 1 Status final
CVSS v3.1 Base Score Severity
Original language Language en
Also referred to

Vulnerability 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.

Vulnerabilities

CVE-2026-10725

Vulnerability 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.

Weakness CWE-409 : Improper Handling of Highly Compressed Data (Data Amplification)

Product status

Known affected
Product Score
Protocol-HTTP2 greater than 0
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

Revision history

Version Date of the revision Summary of the revision
1 Sat Jun 6 00:00:00 2026 First release

Sharing rules

TLP:WHITE
For the TLP version see: https://www.first.org/tlp/