CVE-2026-42505

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreHIGH 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 — 5 sources updated this week
5.3
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 5.3Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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(high)
EPSS
33.8%
KEV
Not listed

Published

July 8, 2026

Last Modified

July 10, 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(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 8× in last 7d / 8× 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. 2026-07-11 10:28 UTCEG score recompute▲ 5.30
  2. 2026-07-11 10:28 UTCGHSA enrichment
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-09 19:10 UTCEPSS rescore
  5. 2026-07-08 19:44 UTCMITRE cvelistV5CVSS v3 → 5.3 · severity → MEDIUM
  6. 2026-07-08 18:52 UTCNVD update
  7. 2026-07-08 16:25 UTCEG score recompute
  8. 2026-07-08 16:24 UTCMITRE cvelistV5first tracked

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 10, 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 33.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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

Explore the affected products and dependency analysis for CVE-2026-42505

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