CVE-2026-33818

Enforce maximum recursion depth in encoding/asn1

High 7.5

Enforce a recursion limit in Unmarshal to prevent stack exhaustion when parsing deeply-nested, recursive structures.

Assigner
Go

Published
2026-08-13

Updated
2026-10-21

Reserved
2026-03-23

Scores

Source	CVSS	Score	Severity	Vector
CISA-ADP	3.1	7.5	High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses

CWE-400

Affected

Vendor	Product	Versions
Go standard library	encoding/asn1	< 1.25.13 (affected) 1.26.0-0 to < 1.26.6 (affected) 1.27.0-0 to < 1.27.0-rc.3 (affected) others: unaffected

References

Full CVE JSON record (5.2)

API · GitHub · cve.org

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "HIGH",
              "baseScore": 7.5,
              "baseSeverity": "HIGH",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-33818",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-08-14T15:11:19.904646Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-400",
                "description": "CWE-400 Uncontrolled Resource Consumption",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-08-14T15:12:34.877Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "encoding/asn1",
          "product": "encoding/asn1",
          "programRoutines": [
            {
              "name": "parseSequenceOf"
            },
            {
              "name": "parseField"
            },
            {
              "name": "UnmarshalWithParams"
            },
            {
              "name": "Unmarshal"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.13",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.6",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.27.0-rc.3",
              "status": "affected",
              "version": "1.27.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Marwan Atia (marwansamir688@gmail.com)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Enforce a recursion limit in Unmarshal to prevent stack exhaustion when parsing deeply-nested, recursive structures."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-21T10:24:46.848Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/80405"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/94pEornpRlI"
        },
        {
          "url": "https://go.dev/cl/814980"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5972"
        }
      ],
      "title": "Enforce maximum recursion depth in encoding/asn1"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-33818",
    "datePublished": "2026-08-13T21:58:52.821Z",
    "dateReserved": "2026-03-23T20:35:32.815Z",
    "dateUpdated": "2026-10-21T10:24:46.848Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}