CVE-2026-47221

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 62% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 7.5Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.18.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, the router filter contains a null pointer dereference vulnerability when handling HTTP 303 (See Other) internal redirects for body-less non-GET/HEAD requests. When a POST, PUT, DELETE, or PATCH request without a body is sent to a route configured with internal redirect policy that includes 303 in redirect_response_codes, and the upstream responds with HTTP 303, the redirect handling code attempts to drain a request body buffer that was never allocated. This results in a segmentation fault that crashes the entire Envoy process. When route configured with internal_redirect_policy including 303 in redirect_response_codes and upstream must return HTTP 303 response, an unauthenticated attacker can exploit this to cause complete denial of service, terminating all active connections. This vulnerability is fixed in 1.35.13, 1.36.9, 1.37.5, and 1.38.3.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
38
EG Risk 38/100

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
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
EPSS PROB
0.4%
EPSS %ILE
36th
KEV
Not listed

Published

June 26, 2026

Last Modified

June 27, 2026

Advisory Details (1)

Auto-updated Jun 26, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Null pointer deref in internal redirects · Advisory · envoyproxy/envoy · GitHub

https://github.com/envoyproxy/envoy/security/advisories/GHSA-rcff-gw58-pjpr

Vendor Advisories for CVE-2026-47221(5)

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

Patch Availability(4)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17849086822026-08-03redhat
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17849535562026-08-03redhat
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17849537432026-08-03redhat
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17849086392026-08-03redhat

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 4× in last 7d / 32× 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.

Showing the most recent 100 of 172 total refreshes for this CVE.

  1. 2026-10-04 23:22 UTCEPSS rescore
  2. 2026-10-03 14:25 UTCEPSS rescore
  3. 2026-10-01 19:50 UTCEPSS rescore
  4. 2026-09-30 15:03 UTCEPSS rescore
  5. 2026-09-28 13:51 UTCEPSS rescore
  6. 2026-09-27 13:48 UTCEPSS rescore
  7. 2026-09-26 15:59 UTCEPSS rescore
  8. 2026-09-26 00:27 UTCEPSS rescore
  9. 2026-09-23 17:53 UTCEPSS rescore
  10. 2026-09-23 07:51 UTCEG score recompute
  11. 2026-09-23 07:51 UTCVendor advisory
  12. 2026-09-20 20:16 UTCEPSS rescore
  13. 2026-09-18 19:28 UTCEPSS rescore
  14. 2026-09-18 07:13 UTCEG score recompute
  15. 2026-09-18 07:13 UTCVendor advisory
  16. 2026-09-16 14:08 UTCEPSS rescore
  17. 2026-09-16 05:15 UTCEPSS rescore
  18. 2026-09-14 01:10 UTCEG score recompute
  19. 2026-09-14 01:10 UTCVendor advisory
  20. 2026-09-13 16:47 UTCEPSS rescore
  21. 2026-09-13 09:32 UTCVendor advisory
  22. 2026-09-12 15:34 UTCEG score recompute
  23. 2026-09-12 15:34 UTCVendor advisory
  24. 2026-09-12 15:01 UTCEPSS rescore
  25. 2026-09-11 14:53 UTCEPSS rescore
Show 75 more
  1. 2026-09-11 09:37 UTCEPSS rescore
  2. 2026-09-10 09:34 UTCEPSS rescore
  3. 2026-09-08 22:00 UTCEPSS rescore
  4. 2026-09-07 16:01 UTCEPSS rescore
  5. 2026-09-06 16:02 UTCEG score recompute
  6. 2026-09-06 16:02 UTCVendor advisory
  7. 2026-09-06 13:47 UTCEPSS rescore
  8. 2026-09-04 05:06 UTCEPSS rescore
  9. 2026-09-02 14:12 UTCEPSS rescore
  10. 2026-09-01 13:54 UTCEPSS rescore
  11. 2026-08-30 19:21 UTCEG score recompute
  12. 2026-08-30 19:21 UTCVendor advisory
  13. 2026-08-30 19:17 UTCEPSS rescore
  14. 2026-08-30 01:22 UTCEPSS rescore
  15. 2026-08-28 21:41 UTCEPSS rescore
  16. 2026-08-27 23:04 UTCEG score recompute
  17. 2026-08-27 23:04 UTCVendor advisory
  18. 2026-08-27 14:25 UTCEPSS rescore
  19. 2026-08-26 14:46 UTCEPSS rescore
  20. 2026-08-25 13:49 UTCEPSS rescore
  21. 2026-08-25 00:31 UTCEG score recompute
  22. 2026-08-25 00:31 UTCVendor advisory
  23. 2026-08-24 12:53 UTCEG score recompute
  24. 2026-08-24 12:53 UTCVendor advisory
  25. 2026-08-23 21:07 UTCVendor advisory
  26. 2026-08-23 09:29 UTCEG score recompute
  27. 2026-08-23 09:29 UTCVendor advisory
  28. 2026-08-23 00:19 UTCEPSS rescore
  29. 2026-08-22 21:51 UTCVendor advisory
  30. 2026-08-22 09:31 UTCEG score recompute
  31. 2026-08-22 09:31 UTCVendor advisory
  32. 2026-08-21 23:49 UTCEPSS rescore
  33. 2026-08-21 17:46 UTCVendor advisory
  34. 2026-08-21 06:07 UTCEG score recompute
  35. 2026-08-21 06:07 UTCVendor advisory
  36. 2026-08-20 22:55 UTCEPSS rescore
  37. 2026-08-20 18:27 UTCVendor advisory
  38. 2026-08-20 06:49 UTCEG score recompute
  39. 2026-08-20 06:49 UTCVendor advisory
  40. 2026-08-19 17:04 UTCEPSS rescore
  41. 2026-08-19 12:37 UTCVendor advisory
  42. 2026-08-18 23:54 UTCEG score recompute
  43. 2026-08-18 23:54 UTCVendor advisory
  44. 2026-08-18 13:48 UTCEPSS rescore
  45. 2026-08-17 13:47 UTCEPSS rescore
  46. 2026-08-17 08:10 UTCVendor advisory
  47. 2026-08-16 20:32 UTCEG score recompute
  48. 2026-08-16 20:32 UTCVendor advisory
  49. 2026-08-16 14:56 UTCEPSS rescore
  50. 2026-08-16 08:53 UTCEG score recompute
  51. 2026-08-16 08:53 UTCVendor advisory
  52. 2026-08-16 02:14 UTCEPSS rescore
  53. 2026-08-15 21:15 UTCVendor advisory
  54. 2026-08-15 09:37 UTCEG score recompute
  55. 2026-08-15 09:37 UTCVendor advisory
  56. 2026-08-15 01:30 UTCEPSS rescore
  57. 2026-08-14 21:58 UTCVendor advisory
  58. 2026-08-14 10:20 UTCVendor advisory
  59. 2026-08-13 22:42 UTCEG score recompute
  60. 2026-08-13 22:42 UTCVendor advisory
  61. 2026-08-13 22:00 UTCEPSS rescore
  62. 2026-08-13 11:03 UTCVendor advisory
  63. 2026-08-12 23:25 UTCEG score recompute
  64. 2026-08-12 23:25 UTCVendor advisory
  65. 2026-08-12 13:51 UTCEPSS rescore
  66. 2026-08-12 11:47 UTCVendor advisory
  67. 2026-08-12 00:09 UTCEG score recompute
  68. 2026-08-12 00:09 UTCVendor advisory
  69. 2026-08-11 12:30 UTCVendor advisory
  70. 2026-08-11 00:52 UTCEG score recompute
  71. 2026-08-11 00:52 UTCVendor advisory
  72. 2026-08-11 00:00 UTCEPSS rescore
  73. 2026-08-10 13:14 UTCVendor advisory
  74. 2026-08-10 01:35 UTCVendor advisory
  75. 2026-08-09 13:57 UTCEG score recompute

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Frequently asked(5)

What is CVE-2026-47221?
CVE-2026-47221 is a high vulnerability published on June 26, 2026. Envoy is an open source edge and service proxy designed for cloud-native applications. From 1.18.0 until 1.35.13, 1.36.9, 1.37.5, and 1.38.3, the router filter contains a null pointer dereference vulnerability when handling HTTP 303 (See Other) internal redirects for body-less non-GET/HEAD…
When was CVE-2026-47221 disclosed?
CVE-2026-47221 was first published on June 26, 2026, with the most recent update on June 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47221 actively exploited?
CVE-2026-47221 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.4% probability of exploitation in the next 30 days (36th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-47221?
CVE-2026-47221 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-47221?
A fix for CVE-2026-47221 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-47221 are linked in the Vendor Advisories panel on this page.

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