Upstream information
Description
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.
SUSE information
Overall state of this security issue: Pending
This issue is currently rated as having important severity.
| CVSS detail | CNA (CISA-ADP) | SUSE |
|---|---|---|
| Base Score | 7.5 | 7.5 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| Attack Vector | Network | Network |
| Attack Complexity | Low | Low |
| Privileges Required | None | None |
| User Interaction | None | None |
| Scope | Unchanged | Unchanged |
| Confidentiality Impact | None | None |
| Integrity Impact | None | None |
| Availability Impact | High | High |
| CVSSv3 Version | 3.1 | 3.1 |
| CVSS detail | SUSE |
|---|---|
| Base Score | 8.7 |
| Vector | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| Attack Vector | Network |
| Attack Complexity | Low |
| Attack Requirements | None |
| Privileges Required | None |
| User Interaction | None |
| Vulnerable System Confidentiality Impact | None |
| Vulnerable System Integrity Impact | None |
| Vulnerable System Availability Impact | High |
| Subsequent System Confidentiality Impact | None |
| Subsequent System Integrity Impact | None |
| Subsequent System Availability Impact | None |
| CVSSv4 Version | 4.0 |
List of released packages
| Product(s) | Fixed package version(s) | References |
|---|---|---|
| openSUSE Tumbleweed |
| Patchnames: openSUSE-Tumbleweed-2026-11735 |
Status of this issue by product and package
Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.
| Product(s) | Source package | State |
|---|---|---|
| Products under general support and receiving all security fixes. | ||
| SUSE Linux Enterprise Module for Package Hub 15 SP7 | perl-Protocol-HTTP2 | Affected |
| SUSE Linux Enterprise Server 16.0 | perl-Protocol-HTTP2 | Affected |
| SUSE Linux Enterprise Server 16.1 | perl-Protocol-HTTP2 | Analysis |
| SUSE Linux Enterprise Server for SAP applications 16.0 | perl-Protocol-HTTP2 | Affected |
| SUSE Linux Enterprise Server for SAP applications 16.1 | perl-Protocol-HTTP2 | Analysis |
| openSUSE Leap 16.0 | perl-Protocol-HTTP2 | Affected |
| Products past their end of life and not receiving proactive updates anymore. | ||
| SUSE Linux Enterprise Module for Package Hub 15 SP6 | perl-Protocol-HTTP2 | Affected |
| openSUSE Leap 15.6 | perl-Protocol-HTTP2 | Affected |
SUSE Timeline for this CVE
CVE page created: Tue Sep 8 14:29:25 2026CVE page last modified: Thu Sep 10 13:47:00 2026