CVE-2024-30255

HTTP/2: CPU exhaustion due to CONTINUATION frame flood

Published Apr 4, 2024 CVSS 3.1 · 5.3 Medium EPSS 85.0% KEV · Not listed
Description
Envoy is a cloud-native, open source edge and service proxy. The HTTP/2 protocol stack in Envoy versions prior to 1.29.3, 1.28.2, 1.27.4, and 1.26.8 are vulnerable to CPU exhaustion due to flood of CONTINUATION frames. Envoy's HTTP/2 codec allows the client to send an unlimited number of CONTINUATION frames even after exceeding Envoy's header map limits. This allows an attacker to send a sequence of CONTINUATION frames without the END_HEADERS bit set causing CPU utilization, consuming approximately 1 core per 300Mbit/s of traffic and culminating in denial of service through CPU exhaustion. Users should upgrade to version 1.29.3, 1.28.2, 1.27.4, or 1.26.8 to mitigate the effects of the CONTINUATION flood. As a workaround, disable HTTP/2 protocol for downstream connections.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Envoyproxy
Envoyproxy envoy
CPEs cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*
Vendors & Products Envoyproxy
Envoyproxy envoy
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat service Mesh
CPEs cpe:/a:redhat:service_mesh:2.5::el8
Vendors & Products Redhat service Mesh
Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 4, 2025, 6:30 PM
Reserved
Mar 26, 2024, 12:52 PM
Status
Modified
Published
Apr 4, 2024, 8:15 PM
Modified
Jun 17, 2026, 7:26 AM
Severity
Moderate
Public date
Apr 3, 2024, 12:00 AM