How severe is CVE-2024-30255?

CVE-2024-30255 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2024-30255 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 88% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2024-30255?

CVE-2024-30255 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2024-30255?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2024-30255 have an EU (EUVD) identifier?

Yes. CVE-2024-30255 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-28182.

When was CVE-2024-30255 published?

CVE-2024-30255 was published on 2024-04-04 and last updated on 2026-06-17.

CVE-2024-30255

CVE-2024-30255 is a medium-severity vulnerability in Envoyproxy Envoy with a CVSS 3.x base score of 5.3. Its EPSS exploit-prediction score of 88% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-390.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 88% (100th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2024-28182
Weakness: CWE-390
Affected product: Envoyproxy Envoy
Published: 2024-04-04
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2024-30255?: 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.
How severe is CVE-2024-30255?: CVE-2024-30255 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2024-30255 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 88% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-30255?: CVE-2024-30255 affects Envoyproxy Envoy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-30255?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2024-30255 have an EU (EUVD) identifier?: Yes. CVE-2024-30255 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-28182.
When was CVE-2024-30255 published?: CVE-2024-30255 was published on 2024-04-04 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*

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