CVE-2024-27919 | HTTP/2: memory exhaustion due to CONTINUATION frame flood

Envoy is a cloud-native, open-source edge and service proxy. In versions 1.29.0 and 1.29.1, theEnvoy HTTP/2 protocol stack is vulnerable to the flood of CONTINUATION frames. Envoy's HTTP/2 codec does not reset a request when header map limits have been exceeded. This allows an attacker to send an sequence of CONTINUATION frames without the END_HEADERS bit set causing unlimited memory consumption. This can lead to denial of service through memory exhaustion. Users should upgrade to versions 1.29.2 to mitigate the effects of the CONTINUATION flood. Note that this vulnerability is a regression in Envoy version 1.29.0 and 1.29.1 only. As a workaround, downgrade to version 1.28.1 or earlier or disable HTTP/2 protocol for downstream connections.

Published: 2024-04-04 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-27919 is rated High Risk (69.9/100): CVSS High severity, with high exploitation likelihood (EPSS 86.75%, 100th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +62.86% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-27919

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 23.88% 86.75% +62.86%
2 2026-04-02 19.05% 23.88% +4.83%
3 2025-11-25 — 19.05% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-27919

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2024-27919

OS Trackers for CVE-2024-27919

vendor priority summary link
redhat high — https://access.redhat.com/security/cve/CVE-2024-27919

Affected software / configurations for CVE-2024-27919

Vendor Product Version Raw CPE
envoyproxy envoy 1.29.0 cpe:2.3:a:envoyproxy:envoy:1.29.0:*:*:*:*:*:*:*
envoyproxy envoy 1.29.1 cpe:2.3:a:envoyproxy:envoy:1.29.1:*:*:*:*:*:*:*

References for CVE-2024-27919

cvelogic Threat Intelligence