CVE-2026-42505

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

Score 5.3 from GitHub Security Advisory published 2026-07-08. CISA-ADP (Vulnrichment) CVSS v3.1 baseline 5.3; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: cisa-adp, epss, ghsa
Trending — 4 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

A fix is available — apply it.

Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
39(Track)
EG Risk 39/100SSVC: 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
Severity53% × 45%
Exploitation0% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
31%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 13, 2026

Advisory Details (4)

Auto-updated Jul 8, 2026
No patch confirmed yet.
generic

GO-2026-5856 - Go Packages

https://pkg.go.dev/vuln/GO-2026-5856
generic
https://groups.google.com/g/golang-announce/c/OrmQE_Yp5Sc
generic

crypto/tls: omit PSK in ECH outer client hello · Issue #79282 · golang/go · GitHub

https://go.dev/issue/79282
generic
https://go.dev/cl/775960

Vendor Advisories for CVE-2026-42505(8)

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

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatrhosdt/opentelemetry-rhel9-operator:17866351752026-08-13redhat
redhatgo-toolset:rhel8-8100020260710105056.a3795dee2026-07-13redhat
redhatgolang-0:1.26.5-1.el9_82026-07-09redhat
redhatgolang-0:1.26.5-1.el10_22026-07-09redhat
redhatgolang1-26-main-1.26.5-0.1.hum12026-07-08redhat
redhatgolang1-25-main-1.25.12-0.1.hum12026-07-08redhat

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.

Affected Packages

(5 across 3 ecosystems)
Debian:14(3)
PackageVulnerable rangeFixed inDependents
golang-1.251.25.0-1 ... 1.25.9-1 (17 versions)1.25.12-1—
golang-1.261.26.0-1 ... 1.26~rc3-2 (15 versions)1.26.5-1—
golang-1.271.27~rc1-11.27~rc2-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
golang-1.241.24.12-1 ... 1.24.9-1 (10 versions)——
Go(1)
PackageVulnerable rangeFixed inDependents
stdlib—1.27.0-rc.2—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 101× 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 150 total refreshes for this CVE.

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

Frequently asked(5)

What is CVE-2026-42505?
CVE-2026-42505 is a medium vulnerability published on July 8, 2026. Handshakes which used Encrypted Client Hello could be de-anonymized by a passive network observer due to a disclosure of pre-shared key identities in the unencrypted client hello.
When was CVE-2026-42505 disclosed?
CVE-2026-42505 was first published in the National Vulnerability Database on July 8, 2026, with the most recent update on July 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-42505 actively exploited?
CVE-2026-42505 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 68.9% of all scored CVEs.
What is the CVSS score of CVE-2026-42505?
CVE-2026-42505 has a CVSS v3.1 base score of 5.3 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending).
How do I remediate CVE-2026-42505?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42505, 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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