CVE-2026-16028Network attack vector

Remote service interruption via retained closed streams

Published Sep 7, 2026 · Updated Sep 8, 2026

Memory exhaustion in Protocol::HTTP2 before 1.14 allows remote attackers to interrupt Perl HTTP/2 services via ordinary closed streams. The stream_state routine clears most keys when a stream closes but leaves its entry in the connection stream table, so increasing stream IDs retain memory for the connection lifetime. A peer needs only one long-lived HTTP/2 connection and sequential accepted streams; either a hostile client or server can exhaust the opposite endpoint's memory and interrupt service.

CVSS severityUnavailable
Unscored
EPSS probability0.63%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory exhaustion in Protocol::HTTP2 before 1.14 allows remote attackers to interrupt Perl HTTP/2 services via ordinary closed streams. The stream_state routine clears most keys when a stream closes but leaves its entry in the connection stream table, so increasing stream IDs retain memory for the connection lifetime. A peer needs only one long-lived HTTP/2 connection and sequential accepted streams; either a hostile client or server can exhaust the opposite endpoint's memory and interrupt service.

The record

CVE
CVE-2026-16028
Published
Sep 7, 2026
Updated
Sep 8, 2026
Vendor
The Perl Foundation
Product
Protocol::HTTP2
Classifications
CWE-401, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 8, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <1.14

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Perl Foundation · Protocol::HTTP2version=0 <1.14

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-401Missing Release of Memory after Effective Lifetime
T1499.003Endpoint Denial of Service: Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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