Protocol::HTTP/2 up to 1.13 Stream.pm memory allocation

Summaryinfo

A vulnerability was found in Protocol::HTTP2 up to 1.13. It has been rated as problematic. This affects an unknown part of the file lib/Protocol/HTTP2/Stream.pm. The manipulation leads to memory allocation. This vulnerability is referenced as CVE-2026-16028. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Protocol::HTTP2 up to 1.13. This issue affects an unknown function of the file lib/Protocol/HTTP2/Stream.pm. The manipulation with an unknown input leads to a memory allocation vulnerability. Using CWE to declare the problem leads to CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. Impacted is availability. The summary by CVE is:

Protocol::HTTP2 versions before 1.14 for Perl allow memory exhaustion via closed streams that stream_state never removes from the connection stream table. When a stream reaches the CLOSED state, stream_state returns the concurrency slot and clears most of the stream's keys, but the entry itself stays in the connection stream table and nothing in the distribution removes it. Stream identifiers increase monotonically, so a peer can open and close streams on one connection indefinitely, each close leaving a residual entry that is retained for the life of the connection. SETTINGS_MAX_CONCURRENT_STREAMS does not bound this. That setting caps how many streams are live at once and is enforced, while the growth is made of streams the cap has already released, so it accumulates with concurrency never exceeding one. The client keeps the same table and grows the same way against a hostile server. Measured against a server built on this module, roughly 920 bytes are retained per closed stream for about 19 bytes on the wire, so 100,000 sequential streams on one connection grow server resident memory by about 88 MiB. The streams are ordinary requests that the application accepts and completes.

The advisory is shared at metacpan.org. The identification of this vulnerability is CVE-2026-16028 since 07/17/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details are known, but no exploit is available.

Upgrading to version 1.14 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-72527). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• Protocol::HTTP2

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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