CVE-2026-48743

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 77% 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, secondary
Trending — 3 sources updated this weekElevated
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%CVSS: 7.5Exploit: Elevated riskExposed: 0

A fix is available — apply it.

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero Content-Length into a complete upstream HTTP/1 request with unresolved body debt. In an HTTP/1 upstream deployment where the origin replies before reading the declared body and keeps the connection reusable, the beginning of the next Envoy-generated upstream request can be consumed as the first request's body. The remaining bytes are then parsed by the origin as a new HTTP/1 request. This was reproduced as a route-bypass/desync: direct /pwn was denied by Envoy, but the second downstream H3 stream received the response for backend-parsed GET /pwn HTTP/1.1. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
50(Track)
EG Risk 50/100SSVC: 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
Severity75% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
23%
KEV
Not listed

Published

June 26, 2026

Last Modified

June 29, 2026

Advisory Details (1)

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

HTTP/3 to HTTP/1 request smuggling via headers-only request with nonzero Content-Length · Advisory · envoyproxy/envoy · GitHub

https://github.com/envoyproxy/envoy/security/advisories/GHSA-8phg-2h2q-jgxf

Vendor Advisories for CVE-2026-48743(3)

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/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 11× in last 7d / 45× 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 156 total refreshes for this CVE.

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

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Frequently asked(5)

What is CVE-2026-48743?
CVE-2026-48743 is a high vulnerability published on June 26, 2026. Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, Envoy can translate a downstream HTTP/3 request that is complete at the transport layer (HEADERS with FIN / headers-only close) but still carries a nonzero…
When was CVE-2026-48743 disclosed?
CVE-2026-48743 was first published in the National Vulnerability Database on June 26, 2026, with the most recent update on June 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-48743 actively exploited?
CVE-2026-48743 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 77.3% of all scored CVEs.
What is the CVSS score of CVE-2026-48743?
CVE-2026-48743 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-48743?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48743, 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.

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