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Unexpected work during chain building in crypto/x509

Type: advisorySource: OSV1 source record

During chain building, the amount of work that is done is not correctly limited when a large number of intermediate certificates are passed in VerifyOptions.Intermediates, which can lead to a denial of service. This affects both direct users of crypto/x509 and users of crypto/tls.

Announced Group revision 1
Original source ↗

GO-2026-4947

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:GO-2026-4947

stdlib

Source reference: /affected/0/package/name

Affected versions
Not stated in this record
Fixed versions
1.25.9

Source reference: /affected/0/ranges

1.26.2

Source reference: /affected/0/ranges

Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "SEMVER",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.25.9"
          },
          {
            "introduced": "1.26.0-0"
          },
          {
            "fixed": "1.26.2"
          }
        ]
      }
    ],
    "package": {
      "name": "stdlib",
      "purl": "pkg:golang/stdlib",
      "ecosystem": "Go"
    },
    "database_specific": {
      "source": "https://vuln.go.dev/ID/GO-2026-4947.json"
    },
    "ecosystem_specific": {
      "imports": [
        {
          "path": "crypto/x509",
          "symbols": [
            "Certificate.Verify",
            "Certificate.buildChains"
          ]
        }
      ]
    }
  }
]
Related CVEs
CVE-2026-32280

Source reference: /aliases

Publisher severity

No explicit severity was provided.

Event
#75186 · Revision 1
Added to Heist Feed
Publisher date
Read the original announcement