Vulnerability · Published Jun 6, 2026 · Assigned by CPANSec
CVE-2026-10725Protocol::HTTP2 versions before 1.13 for Perl is vulnerable to a HTTP/2 Bomb
High 7.5
In plain English
A high-severity security flaw in Protocol::HTTP2 from CRUX. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | perl-protocol-http2 | 1.14-r0 | ALPINE-CVE-2026-10725 |
| Alpine:v3.24 | perl-protocol-http2 | 1.14-r0 | ALPINE-CVE-2026-10725 |
| Debian:12 | libprotocol-http2-perl | no fix listed | DEBIAN-CVE-2026-10725 |
| Debian:13 | libprotocol-http2-perl | no fix listed | DEBIAN-CVE-2026-10725 |
| Debian:14 | libprotocol-http2-perl | 1.12-2 | DEBIAN-CVE-2026-10725 |
| Ubuntu:22.04:LTS | libprotocol-http2-perl | no fix listed | UBUNTU-CVE-2026-10725 |
| Ubuntu:24.04:LTS | libprotocol-http2-perl | no fix listed | UBUNTU-CVE-2026-10725 |
| Ubuntu:25.10 | libprotocol-http2-perl | no fix listed | UBUNTU-CVE-2026-10725 |
| Ubuntu:26.04:LTS | libprotocol-http2-perl | no fix listed | UBUNTU-CVE-2026-10725 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| CRUX | Protocol::HTTP2 | 0 – before 1.13 |
Weakness: CWE-409 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://metacpan.org/release/CRUX/Protocol-HTTP2-1.13/changes release-notes
- https://metacpan.org/release/CRUX/Protocol-HTTP2-1.12/source/lib/Protocol/HTTP2/HeaderCompression.pm#L133
- https://metacpan.org/release/CRUX/Protocol-HTTP2-1.12/source/lib/Protocol/HTTP2/Stream.pm#L414
- https://github.com/vlet/p5-Protocol-HTTP2/commit/822bf22224adbd662e8d0b865eeacb2b294d16cd.patch patch
- https://security.metacpan.org/patches/P/Protocol-HTTP2/1.12/CVE-2026-10725-r2.patch patch
- http://www.openwall.com/lists/oss-security/2026/06/06/7