CVE-2026-39819 (GCVE-0-2026-39819)

Vulnerability from cvelistv5 – Published: 2026-05-07 19:41 – Updated: 2026-05-08 21:29
VLAI?
Title
Invoking "go bug" follows symlinks in predictable temporary filenames in cmd/go
Summary
The "go bug" command writes to two files with predictable names in the system temporary directory (for example, "/tmp"). An attacker with access to the temporary directory can create a symlink in one of these names, causing "go bug" to overwrite the target of the symlink.
Severity ?
5.3 (Medium)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N
CWE
  • CWE-377 - Insecure Temporary File
Assigner
Go
References
Impacted products
Vendor Product Version
Go toolchain cmd/go Affected: 0 , < 1.25.10 (semver)
Affected: 1.26.0-0 , < 1.26.3 (semver)
Create a notification for this product.
Credits
Harshit Gupta (Mr HAX)
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "HIGH",
              "attackVector": "LOCAL",
              "availabilityImpact": "NONE",
              "baseScore": 5.3,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "LOW",
              "integrityImpact": "HIGH",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-39819",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-08T16:56:43.015860Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-08T21:29:53.674Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "cmd/go",
          "product": "cmd/go",
          "vendor": "Go toolchain",
          "versions": [
            {
              "lessThan": "1.25.10",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.3",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Harshit Gupta (Mr HAX)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The \"go bug\" command writes to two files with predictable names in the system temporary directory (for example, \"/tmp\"). An attacker with access to the temporary directory can create a symlink in one of these names, causing \"go bug\" to overwrite the target of the symlink."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-377: Insecure Temporary File",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-07T19:41:18.849Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/78584"
        },
        {
          "url": "https://go.dev/cl/763882"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/qcCIEXso47M"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-4978"
        }
      ],
      "title": "Invoking \"go bug\" follows symlinks in predictable temporary filenames in cmd/go"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-39819",
    "datePublished": "2026-05-07T19:41:18.849Z",
    "dateReserved": "2026-04-07T18:13:03.526Z",
    "dateUpdated": "2026-05-08T21:29:53.674Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-39819",
      "date": "2026-05-22",
      "epss": "9e-05",
      "percentile": "0.00861"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-39819\",\"sourceIdentifier\":\"security@golang.org\",\"published\":\"2026-05-07T20:16:43.083\",\"lastModified\":\"2026-05-13T15:05:41.943\",\"vulnStatus\":\"Analyzed\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The \\\"go bug\\\" command writes to two files with predictable names in the system temporary directory (for example, \\\"/tmp\\\"). An attacker with access to the temporary directory can create a symlink in one of these names, causing \\\"go bug\\\" to overwrite the target of the symlink.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N\",\"baseScore\":5.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.0,\"impactScore\":4.2},{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N\",\"baseScore\":5.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"HIGH\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"LOW\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.0,\"impactScore\":4.2}]},\"weaknesses\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-59\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"1.25.10\",\"matchCriteriaId\":\"1C966EF3-C51C-4239-B5FC-C44A5202FEC8\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:golang:go:*:*:*:*:*:*:*:*\",\"versionStartIncluding\":\"1.26.0\",\"versionEndExcluding\":\"1.26.3\",\"matchCriteriaId\":\"522E4CD0-2B99-4363-9C78-0BAFD988A2D6\"}]}]}],\"references\":[{\"url\":\"https://go.dev/cl/763882\",\"source\":\"security@golang.org\",\"tags\":[\"Patch\"]},{\"url\":\"https://go.dev/issue/78584\",\"source\":\"security@golang.org\",\"tags\":[\"Issue Tracking\"]},{\"url\":\"https://groups.google.com/g/golang-announce/c/qcCIEXso47M\",\"source\":\"security@golang.org\",\"tags\":[\"Issue Tracking\",\"Mailing List\"]},{\"url\":\"https://pkg.go.dev/vuln/GO-2026-4978\",\"source\":\"security@golang.org\",\"tags\":[\"Vendor Advisory\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 5.3, \"attackVector\": \"LOCAL\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"HIGH\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"LOW\", \"confidentialityImpact\": \"LOW\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-39819\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-05-08T16:56:43.015860Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-05-08T16:57:14.663Z\"}}], \"cna\": {\"title\": \"Invoking \\\"go bug\\\" follows symlinks in predictable temporary filenames in cmd/go\", \"credits\": [{\"lang\": \"en\", \"value\": \"Harshit Gupta (Mr HAX)\"}], \"affected\": [{\"vendor\": \"Go toolchain\", \"product\": \"cmd/go\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"1.25.10\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"1.26.0-0\", \"lessThan\": \"1.26.3\", \"versionType\": \"semver\"}], \"packageName\": \"cmd/go\", \"collectionURL\": \"https://pkg.go.dev\", \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://go.dev/issue/78584\"}, {\"url\": \"https://go.dev/cl/763882\"}, {\"url\": \"https://groups.google.com/g/golang-announce/c/qcCIEXso47M\"}, {\"url\": \"https://pkg.go.dev/vuln/GO-2026-4978\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"The \\\"go bug\\\" command writes to two files with predictable names in the system temporary directory (for example, \\\"/tmp\\\"). An attacker with access to the temporary directory can create a symlink in one of these names, causing \\\"go bug\\\" to overwrite the target of the symlink.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"description\": \"CWE-377: Insecure Temporary File\"}]}], \"providerMetadata\": {\"orgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"shortName\": \"Go\", \"dateUpdated\": \"2026-05-07T19:41:18.849Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-39819\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-08T21:29:53.674Z\", \"dateReserved\": \"2026-04-07T18:13:03.526Z\", \"assignerOrgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"datePublished\": \"2026-05-07T19:41:18.849Z\", \"assignerShortName\": \"Go\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.