CVE-2026-47778

MEDIUMPre-NVD 4.44.4—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 4.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 88% 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
4.4EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 4.4Exploit: 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. Prior to 1.35.11, 1.36.7, 1.37.3, and 1.38.1, a structural flaw was identified in DefaultCertValidator::verifySubjectAltName where the extracted DNS SAN string is cast to a C-style string using .c_str() before being passed to the Utility::dnsNameMatch() algorithm. If the attacker serves a certificate with a dNSName SAN containing an embedded NUL byte, the helper Utility::generalNameAsString captures the complete string including the NUL. However, when .c_str() evaluates it, implicit conversion to absl::string_view inside dnsNameMatch relies on strlen(), prematurely truncating the evaluation context. Envoy evaluates trucated string against the exact required config_san match and returns true, thereby successfully validating the string with the Nul byte for an upstream routing. This vulnerability is fixed in 1.35.11, 1.36.7, 1.37.3, and 1.38.1.

CVSS v3
4.4
EG Score
4.4MEDIUMmedium confidence
EG Risk
24
EG Risk 24/100

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
Severity44% × 45%
Exploitation0% × 40%
Automatability30% × 15%
EPSS PROB
0.2%
EPSS %ILE
10th
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

Embedded NUL in TLS DNS SAN Truncation in the Default TLS Certificate Validator. (Auth Bypass) · Advisory · envoyproxy/envoy · GitHub

https://github.com/envoyproxy/envoy/security/advisories/GHSA-f8x4-rw5x-f3r7

Vendor Advisories for CVE-2026-47778(1)

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

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 4× in last 7d / 24× 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 111 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. 2026-09-20 20:16 UTCEPSS rescore
  12. 2026-09-18 19:28 UTCEPSS rescore
  13. 2026-09-18 07:12 UTCEG score recompute
  14. 2026-09-16 14:08 UTCEPSS rescore
  15. 2026-09-16 05:15 UTCEPSS rescore
  16. 2026-09-14 01:10 UTCEG score recompute
  17. 2026-09-13 16:47 UTCEPSS rescore
  18. 2026-09-12 15:34 UTCEG score recompute
  19. 2026-09-11 14:53 UTCEPSS rescore
  20. 2026-09-10 09:35 UTCEPSS rescore
  21. 2026-09-08 22:00 UTCEPSS rescore
  22. 2026-09-07 16:01 UTCEPSS rescore
  23. 2026-09-06 16:02 UTCEG score recompute
  24. 2026-09-06 13:47 UTCEPSS rescore
  25. 2026-09-04 05:06 UTCEPSS rescore
Show 75 more
  1. 2026-09-02 14:12 UTCEPSS rescore
  2. 2026-09-01 13:54 UTCEPSS rescore
  3. 2026-08-30 19:21 UTCEG score recompute
  4. 2026-08-30 19:17 UTCEPSS rescore
  5. 2026-08-30 01:22 UTCEPSS rescore
  6. 2026-08-28 21:41 UTCEPSS rescore
  7. 2026-08-27 23:04 UTCEG score recompute
  8. 2026-08-27 14:25 UTCEPSS rescore
  9. 2026-08-26 14:46 UTCEPSS rescore
  10. 2026-08-25 13:49 UTCEPSS rescore
  11. 2026-08-24 12:53 UTCEG score recompute
  12. 2026-08-22 09:30 UTCEG score recompute
  13. 2026-08-21 23:49 UTCEPSS rescore
  14. 2026-08-21 08:08 UTCEG score recompute
  15. 2026-08-20 22:55 UTCEPSS rescore
  16. 2026-08-20 06:48 UTCEG score recompute
  17. 2026-08-19 17:04 UTCEPSS rescore
  18. 2026-08-18 23:54 UTCEG score recompute
  19. 2026-08-18 13:48 UTCEPSS rescore
  20. 2026-08-17 13:47 UTCEPSS rescore
  21. 2026-08-17 07:31 UTCEG score recompute
  22. 2026-08-16 14:56 UTCEPSS rescore
  23. 2026-08-16 06:11 UTCEG score recompute
  24. 2026-08-16 02:14 UTCEPSS rescore
  25. 2026-08-15 04:51 UTCEG score recompute
  26. 2026-08-15 01:30 UTCEPSS rescore
  27. 2026-08-14 03:31 UTCEG score recompute
  28. 2026-08-13 22:00 UTCEPSS rescore
  29. 2026-08-13 02:10 UTCEG score recompute
  30. 2026-08-12 13:51 UTCEPSS rescore
  31. 2026-08-12 00:50 UTCEG score recompute
  32. 2026-08-11 00:00 UTCEPSS rescore
  33. 2026-08-09 22:10 UTCEG score recompute
  34. 2026-08-09 13:46 UTCEPSS rescore
  35. 2026-08-07 19:29 UTCEG score recompute
  36. 2026-08-06 18:09 UTCEG score recompute
  37. 2026-08-06 13:47 UTCEPSS rescore
  38. 2026-08-05 19:17 UTCEPSS rescore
  39. 2026-08-05 16:49 UTCEG score recompute
  40. 2026-08-04 15:10 UTCEPSS rescore
  41. 2026-08-04 14:57 UTCEG score recompute
  42. 2026-08-04 10:39 UTCEPSS rescore
  43. 2026-08-03 10:36 UTCEPSS rescore
  44. 2026-08-02 05:06 UTCEG score recompute
  45. 2026-08-02 02:27 UTCEPSS rescore
  46. 2026-08-01 04:16 UTCEPSS rescore
  47. 2026-07-31 02:12 UTCEG score recompute
  48. 2026-07-30 16:28 UTCEPSS rescore
  49. 2026-07-30 01:30 UTCEPSS rescore
  50. 2026-07-28 20:25 UTCEG score recompute
  51. 2026-07-28 15:37 UTCEPSS rescore
  52. 2026-07-27 17:06 UTCEG score recompute
  53. 2026-07-26 14:54 UTCEPSS rescore
  54. 2026-07-26 14:34 UTCEG score recompute
  55. 2026-07-24 14:18 UTCEPSS rescore
  56. 2026-07-23 14:18 UTCEPSS rescore
  57. 2026-07-23 03:17 UTCEG score recompute
  58. 2026-07-22 14:08 UTCEPSS rescore
  59. 2026-07-21 15:24 UTCEPSS rescore
  60. 2026-07-20 17:08 UTCEPSS rescore
  61. 2026-07-19 14:31 UTCEPSS rescore
  62. 2026-07-19 02:29 UTCEPSS rescore
  63. 2026-07-18 10:04 UTCEPSS rescore
  64. 2026-07-16 17:03 UTCEPSS rescore
  65. 2026-07-15 16:57 UTCEPSS rescore
  66. 2026-07-15 02:00 UTCEPSS rescore
  67. 2026-07-13 22:30 UTCEPSS rescore
  68. 2026-07-13 06:13 UTCEPSS rescore
  69. 2026-07-12 05:46 UTCEPSS rescore
  70. 2026-07-11 08:27 UTCEPSS rescore
  71. 2026-07-09 19:10 UTCEPSS rescore
  72. 2026-07-08 15:16 UTCEPSS rescore
  73. 2026-07-07 13:46 UTCEPSS rescore
  74. 2026-07-06 16:27 UTCEPSS rescore
  75. 2026-07-06 02:23 UTCEPSS rescore

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-47778?
CVE-2026-47778 is a medium 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, a structural flaw was identified in DefaultCertValidator::verifySubjectAltName where the extracted DNS SAN string is cast to a C-style string using .cstr() before…
When was CVE-2026-47778 disclosed?
CVE-2026-47778 was first published 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-2026-47778 actively exploited?
CVE-2026-47778 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (10th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-47778?
CVE-2026-47778 has a CVSS base score of 4.4 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-47778?
A fix for CVE-2026-47778 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-47778 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-47778

Explore →

Is Your Infrastructure Affected by CVE-2026-47778?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs