CVE-2024-30255

MEDIUMNVD 5.39.0▲
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because EPSS predicts 89% probability of exploitation within the next 30 days (top 0.5% of all CVEs). NVD baseline CVSS 5.3 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, nvd
Elevated
5.3
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 88%
CISA-KEV: Not listedEPSS: 88%CVSS: 5.3Exploit: NoneExposed: 0

A fix is available — apply it.

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.

CVSS v3
5.3
EG Score
9.0(high)
EG Risk
—
EPSS
99.7%
KEV
Not listed

Published

April 4, 2024

Last Modified

November 4, 2025

References (7)

Vendor Advisories for CVE-2024-30255(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(2)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatopenshift-service-mesh/ratelimit-rhel8:2.5.5-32024-10-07redhat
redhatrhmtc/openshift-migration-velero-plugin-for-gcp-rhel8:v1.7.16-62024-07-11redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 3× in last 7d / 16× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:07 UTCEPSS rescore
  2. 2026-07-20 17:06 UTCEPSS rescore
  3. 2026-07-16 17:01 UTCEPSS rescore
  4. 2026-07-15 01:59 UTCEPSS rescore
  5. 2026-07-15 01:59 UTCEPSS rescore
  6. 2026-07-14 14:55 UTCOSV refresh
  7. 2026-07-13 06:11 UTCEPSS rescore
  8. 2026-07-09 19:09 UTCEPSS rescore
  9. 2026-07-08 15:13 UTCEPSS rescore
  10. 2026-07-04 06:30 UTCEPSS rescore
  11. 2026-07-01 15:05 UTCEPSS rescore
  12. 2026-06-26 15:39 UTCOSV refresh
  13. 2026-06-25 13:49 UTCEPSS rescore
  14. 2026-06-25 13:48 UTCEPSS rescore
  15. 2026-06-23 21:32 UTCEPSS rescore
  16. 2026-06-23 21:32 UTCEPSS rescore
  17. 2026-06-17 17:52 UTCEPSS rescore
  18. 2026-06-17 17:52 UTCEPSS rescore
  19. 2026-06-15 17:47 UTCEPSS rescore
  20. 2026-06-12 23:11 UTCEPSS rescore
  21. 2026-06-12 23:11 UTCEPSS rescore
  22. 2026-06-11 13:59 UTCEPSS rescore
  23. 2026-06-10 22:17 UTCEPSS rescore
  24. 2026-06-10 13:21 UTCEPSS rescore
  25. 2026-06-10 13:21 UTCEPSS rescore
Show 21 more
  1. 2026-06-08 22:07 UTCOSV refresh
  2. 2026-06-07 15:24 UTCEPSS rescore
  3. 2026-06-07 15:24 UTCEPSS rescore
  4. 2026-06-05 22:46 UTCEPSS rescore
  5. 2026-06-05 22:46 UTCEPSS rescore
  6. 2026-06-02 20:12 UTCEPSS rescore
  7. 2026-06-02 20:12 UTCEPSS rescore
  8. 2026-06-01 13:51 UTCEPSS rescore
  9. 2026-06-01 13:51 UTCEPSS rescore
  10. 2026-06-01 13:51 UTCEPSS rescore
  11. 2026-05-31 00:15 UTCEPSS rescore
  12. 2026-05-31 00:15 UTCEPSS rescore
  13. 2026-05-29 13:43 UTCEPSS rescore
  14. 2026-05-29 13:43 UTCEPSS rescore
  15. 2026-05-28 13:44 UTCEPSS rescore
  16. 2026-05-28 13:44 UTCEPSS rescore
  17. 2026-05-28 13:44 UTCEPSS rescore
  18. 2026-05-26 07:18 UTCEPSS rescore
  19. 2026-05-26 07:18 UTCEPSS rescore
  20. 2026-05-24 05:10 UTCEG score recompute
  21. 2026-05-24 05:10 UTCVendor advisory

Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 GitHub PoC). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCblackmagic2023/Envoy-CPU-Exhaustion-Vulnerability-PoC
    First seen Apr 9, 2024

    CVE-2024-30255 This repository contains a proof-of-concept (PoC) Python script to demonstrate the CPU exhaustion vulnerability in Envoy caused by a flood of CONTINUATION frames.

    Open source ↗

Frequently asked(5)

What is CVE-2024-30255?
CVE-2024-30255 is a medium vulnerability published on April 4, 2024. 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…
When was CVE-2024-30255 disclosed?
CVE-2024-30255 was first published in the National Vulnerability Database on April 4, 2024, with the most recent update on November 4, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2024-30255 actively exploited?
CVE-2024-30255 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 99.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2024-30255?
CVE-2024-30255 has a CVSS v3 base score of 5.3 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.
How do I remediate CVE-2024-30255?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2024-30255, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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