CVE-2024-30255

CRITICALNVD 5.39.0
EchelonGraph scoreHIGH confidence

Score elevated to 9.0 because EPSS predicts 88% probability of exploitation within the next 30 days (top 0.3% of all CVEs). NVD baseline CVSS 5.3 retained for reference. Confidence: see factors.

Triggered by: EPSS exploit prediction ≥85%
Sources: epss, nvd
Elevated
9.0EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 88%
CISA-KEV: Not listedEPSS PROB: 88%CVSS: 5.3Exploit: Elevated riskExposed: 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
91(Track)
EG Risk 91/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity90% × 45%
Exploitation88% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
88%
EPSS %ILE
100%
KEV
Not listed

Published

April 4, 2024

Last Modified

November 4, 2025

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 / 17× 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. 2026-09-18 19:26 UTCEPSS rescore
  2. 2026-09-16 14:06 UTCEPSS rescore
  3. 2026-09-16 14:06 UTCEPSS rescore
  4. 2026-09-11 09:35 UTCEPSS rescore
  5. 2026-09-07 15:59 UTCEPSS rescore
  6. 2026-09-06 13:46 UTCEPSS rescore
  7. 2026-09-06 13:46 UTCEPSS rescore
  8. 2026-09-05 15:26 UTCEPSS rescore
  9. 2026-09-04 13:58 UTCEPSS rescore
  10. 2026-09-04 05:05 UTCEPSS rescore
  11. 2026-09-03 01:29 UTCOSV refresh
  12. 2026-08-30 19:15 UTCEPSS rescore
  13. 2026-08-28 21:39 UTCEPSS rescore
  14. 2026-08-26 14:44 UTCEPSS rescore
  15. 2026-08-24 14:15 UTCEPSS rescore
  16. 2026-08-21 23:47 UTCEPSS rescore
  17. 2026-08-20 22:53 UTCEPSS rescore
  18. 2026-08-16 14:00 UTCOSV refresh
  19. 2026-08-16 02:13 UTCEPSS rescore
  20. 2026-08-12 13:49 UTCEPSS rescore
  21. 2026-08-02 02:25 UTCEPSS rescore
  22. 2026-08-02 02:25 UTCEPSS rescore
  23. 2026-08-01 08:06 UTCOSV refresh
  24. 2026-07-30 16:26 UTCEPSS rescore
  25. 2026-07-30 16:26 UTCEPSS rescore
Show 50 more
  1. 2026-07-30 01:29 UTCEPSS rescore
  2. 2026-07-28 15:34 UTCEPSS rescore
  3. 2026-07-24 14:16 UTCEPSS rescore
  4. 2026-07-23 02:36 UTCEG score recompute
  5. 2026-07-22 14:07 UTCEPSS rescore
  6. 2026-07-20 17:06 UTCEPSS rescore
  7. 2026-07-16 17:01 UTCEPSS rescore
  8. 2026-07-15 01:59 UTCEPSS rescore
  9. 2026-07-15 01:59 UTCEPSS rescore
  10. 2026-07-14 14:55 UTCOSV refresh
  11. 2026-07-13 06:11 UTCEPSS rescore
  12. 2026-07-09 19:09 UTCEPSS rescore
  13. 2026-07-08 15:13 UTCEPSS rescore
  14. 2026-07-04 06:30 UTCEPSS rescore
  15. 2026-07-01 15:05 UTCEPSS rescore
  16. 2026-06-26 15:39 UTCOSV refresh
  17. 2026-06-25 13:49 UTCEPSS rescore
  18. 2026-06-25 13:48 UTCEPSS rescore
  19. 2026-06-23 21:32 UTCEPSS rescore
  20. 2026-06-23 21:32 UTCEPSS rescore
  21. 2026-06-17 17:52 UTCEPSS rescore
  22. 2026-06-17 17:52 UTCEPSS rescore
  23. 2026-06-15 17:47 UTCEPSS rescore
  24. 2026-06-12 23:11 UTCEPSS rescore
  25. 2026-06-12 23:11 UTCEPSS rescore
  26. 2026-06-11 13:59 UTCEPSS rescore
  27. 2026-06-10 22:17 UTCEPSS rescore
  28. 2026-06-10 13:21 UTCEPSS rescore
  29. 2026-06-10 13:21 UTCEPSS rescore
  30. 2026-06-08 22:07 UTCOSV refresh
  31. 2026-06-07 15:24 UTCEPSS rescore
  32. 2026-06-07 15:24 UTCEPSS rescore
  33. 2026-06-05 22:46 UTCEPSS rescore
  34. 2026-06-05 22:46 UTCEPSS rescore
  35. 2026-06-02 20:12 UTCEPSS rescore
  36. 2026-06-02 20:12 UTCEPSS rescore
  37. 2026-06-01 13:51 UTCEPSS rescore
  38. 2026-06-01 13:51 UTCEPSS rescore
  39. 2026-06-01 13:51 UTCEPSS rescore
  40. 2026-05-31 00:15 UTCEPSS rescore
  41. 2026-05-31 00:15 UTCEPSS rescore
  42. 2026-05-29 13:43 UTCEPSS rescore
  43. 2026-05-29 13:43 UTCEPSS rescore
  44. 2026-05-28 13:44 UTCEPSS rescore
  45. 2026-05-28 13:44 UTCEPSS rescore
  46. 2026-05-28 13:44 UTCEPSS rescore
  47. 2026-05-26 07:18 UTCEPSS rescore
  48. 2026-05-26 07:18 UTCEPSS rescore
  49. 2026-05-24 05:10 UTCEG score recompute
  50. 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 critical 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 88% probability of exploitation in the next 30 days, which ranks it in the top 0.2% of all scored CVEs.
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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