CVE-2026-10725
Protocol::HTTP2 versions before 1.13 for Perl is vulnerable to a HTTP/2 Bomb.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.41%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.41% probability · 35th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-409
- Affected
- crux/protocol\
- Source
- 9b29abf9-4ab0-4765-b253-1875cd9b441e
References
- https://github.com/vlet/p5-Protocol-HTTP2/commit/822bf22224adbd662e8d0b865eeacb2b294d16cd.patchPatch
- https://metacpan.org/release/CRUX/Protocol-HTTP2-1.12/source/lib/Protocol/HTTP2/HeaderCompression.pm#L133Product
- https://metacpan.org/release/CRUX/Protocol-HTTP2-1.12/source/lib/Protocol/HTTP2/Stream.pm#L414Product
- https://metacpan.org/release/CRUX/Protocol-HTTP2-1.13/changesRelease Notes
- https://security.metacpan.org/patches/P/Protocol-HTTP2/1.12/CVE-2026-10725-r2.patchPatch
- http://www.openwall.com/lists/oss-security/2026/06/06/7Mailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.