CVE-2026-42505

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Source
https://cve.org/CVERecord?id=CVE-2026-42505
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42505.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-42505
Aliases
Downstream
Related
Published
2026-07-08T15:46:33Z
Modified
2026-09-18T03:46:32Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
Summary
Invoking Encrypted Client Hello privacy leak in crypto/tls
Details

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.

Database specific 
{
    "cna_assigner": "Go",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42505.json",
    "unresolved_ranges": [
        {
            "extracted_events": [
                {
                    "fixed": "1.25.12"
                },
                {
                    "introduced": "1.26.0-0"
                },
                {
                    "fixed": "1.26.5"
                },
                {
                    "introduced": "1.27.0-0"
                },
                {
                    "fixed": "1.27.0-rc.2"
                }
            ],
            "source": "AFFECTED_FIELD"
        }
    ]
}
References

Affected packages

Git / github.com/golang/go

Affected ranges

Type
GIT
Repo
https://github.com/golang/go
Events
Introduced
6885bad7dd86880be6929c02085e5c7a67ff2887
Fixed
d80d9a98f7e3a8f9b3a82d2c6079f84eb1101d46
Introduced
d90b98e65320778f3b1f99a6951ab20f04d218b3
Fixed
c19862e5f8415b4f24b189d065ed739517c548ba
Introduced
eefb454307250192f45fa3718685e4c0a90e281d
Last Affected
eefb454307250192f45fa3718685e4c0a90e281d
Database specific
Show details 
{
    "cpe": [
        "cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*",
        "cpe:2.3:a:golang:go:1.27:rc1:*:*:*:*:*:*"
    ],
    "extracted_events": [
        {
            "introduced": "1.23.0"
        },
        {
            "fixed": "1.25.12"
        },
        {
            "introduced": "1.26.0"
        },
        {
            "fixed": "1.26.5"
        },
        {
            "introduced": "1.27-rc1"
        },
        {
            "last_affected": "1.27-rc1"
        }
    ],
    "source": [
        "CPE_RANGE",
        "CPE_STRING"
    ]
}

Affected versions

1.*
1.27-rc1
go1.*
go1.26.0
go1.26.1
go1.26.2
go1.26.3
go1.26.4
go1.27rc1

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42505.json"