GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-42507 (GCVE-0-2026-42507)

Vulnerability from cvelistv5 – Published: 2026-06-02 22:01 – Updated: 2026-06-03 19:04
VLAI
Title
Arbitrary inputs are included in errors without any escaping in net/textproto
Summary
When returning errors, functions in the net/textproto package would include its input as part of the error. This might allow an attacker to inject misleading content to errors that are printed or logged.
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-06-03 19:04 UTC
CWE
  • CWE-532 - Insertion of Sensitive Information into Log File
Assigner
References
Impacted products
Vendor Product Version CPE status
Go standard library net/textproto Affected: 0 , < 1.25.11 (semver)
Affected: 1.26.0-0 , < 1.26.4 (semver)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "NETWORK",
              "availabilityImpact": "NONE",
              "baseScore": 5.3,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "LOW",
              "privilegesRequired": "NONE",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2026-42507",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-03T19:04:08.223332Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-03T19:04:45.361Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pkg.go.dev",
          "defaultStatus": "unaffected",
          "packageName": "net/textproto",
          "product": "net/textproto",
          "programRoutines": [
            {
              "name": "parseCodeLine"
            },
            {
              "name": "Reader.ReadCodeLine"
            },
            {
              "name": "readMIMEHeader"
            },
            {
              "name": "Error.Error"
            },
            {
              "name": "Reader.ReadMIMEHeader"
            },
            {
              "name": "Reader.ReadResponse"
            }
          ],
          "vendor": "Go standard library",
          "versions": [
            {
              "lessThan": "1.25.11",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThan": "1.26.4",
              "status": "affected",
              "version": "1.26.0-0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "When returning errors, functions in the net/textproto package would include its input as part of the error. This might allow an attacker to inject misleading content to errors that are printed or logged."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "description": "CWE-532: Insertion of Sensitive Information into Log File",
              "lang": "en"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-02T22:01:37.307Z",
        "orgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
        "shortName": "Go"
      },
      "references": [
        {
          "url": "https://go.dev/issue/79346"
        },
        {
          "url": "https://go.dev/cl/777060"
        },
        {
          "url": "https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw"
        },
        {
          "url": "https://pkg.go.dev/vuln/GO-2026-5039"
        }
      ],
      "title": "Arbitrary inputs are included in errors without any escaping in net/textproto"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "1bb62c36-49e3-4200-9d77-64a1400537cc",
    "assignerShortName": "Go",
    "cveId": "CVE-2026-42507",
    "datePublished": "2026-06-02T22:01:37.307Z",
    "dateReserved": "2026-04-28T00:21:12.792Z",
    "dateUpdated": "2026-06-03T19:04:45.361Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-42507",
      "date": "2026-09-10",
      "epss": "0.0037",
      "percentile": "0.30348"
    },
    "microsoft_vex": {
      "current_release_date": "2026-09-09T14:48:05.000Z",
      "cve": "CVE-2026-42507",
      "id": "msrc_CVE-2026-42507",
      "initial_release_date": "2026-06-05T01:02:17.000Z",
      "product_status:fixed": "3",
      "product_status:known_affected": "7",
      "product_status:known_not_affected": "3",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "Arbitrary inputs are included in errors without any escaping in net/textproto",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-42507.json",
      "version": "9"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-42507\",\"sourceIdentifier\":\"security@golang.org\",\"published\":\"2026-06-02T23:16:38.027\",\"lastModified\":\"2026-07-22T19:10:00.120\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"When returning errors, functions in the net/textproto package would include its input as part of the error. This might allow an attacker to inject misleading content to errors that are printed or logged.\"},{\"lang\":\"es\",\"value\":\"Al devolver errores, las funciones en el paquete net/textproto incluir\u00edan su entrada como parte del error. Esto podr\u00eda permitir a un atacante inyectar contenido enga\u00f1oso en errores que son impresos o registrados.\"}],\"affected\":[{\"source\":\"security@golang.org\",\"affectedData\":[{\"vendor\":\"Go standard library\",\"product\":\"net/textproto\",\"defaultStatus\":\"unaffected\",\"collectionURL\":\"https://pkg.go.dev\",\"packageName\":\"net/textproto\",\"programRoutines\":[{\"name\":\"parseCodeLine\"},{\"name\":\"Reader.ReadCodeLine\"},{\"name\":\"readMIMEHeader\"},{\"name\":\"Error.Error\"},{\"name\":\"Reader.ReadMIMEHeader\"},{\"name\":\"Reader.ReadResponse\"}],\"versions\":[{\"version\":\"0\",\"lessThan\":\"1.25.11\",\"versionType\":\"semver\",\"status\":\"affected\"},{\"version\":\"1.26.0-0\",\"lessThan\":\"1.26.4\",\"versionType\":\"semver\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N\",\"baseScore\":5.3,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"LOW\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":3.9,\"impactScore\":1.4}],\"ssvcV203\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"ssvcData\":{\"timestamp\":\"2026-06-03T19:04:08.223332Z\",\"id\":\"CVE-2026-42507\",\"options\":[{\"exploitation\":\"none\"},{\"automatable\":\"yes\"},{\"technicalImpact\":\"partial\"}],\"role\":\"CISA Coordinator\",\"version\":\"2.0.3\"}}]},\"references\":[{\"url\":\"https://go.dev/cl/777060\",\"source\":\"security@golang.org\"},{\"url\":\"https://go.dev/issue/79346\",\"source\":\"security@golang.org\"},{\"url\":\"https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw\",\"source\":\"security@golang.org\"},{\"url\":\"https://pkg.go.dev/vuln/GO-2026-5039\",\"source\":\"security@golang.org\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-09-08T13:35:34+00:00",
      "cve": "CVE-2026-42507",
      "id": "CVE-2026-42507",
      "initial_release_date": "2026-06-02T22:01:37.307000+00:00",
      "product_status:fixed": "214",
      "product_status:known_affected": "384",
      "product_status:known_not_affected": "181",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "net/textproto: golang: Golang net/textproto: Misleading error messages via input injection",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42507.json",
      "version": "3"
    },
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 5.3, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N\", \"integrityImpact\": \"LOW\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}, {\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-42507\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-06-03T19:04:08.223332Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-06-03T19:04:38.365Z\"}}], \"cna\": {\"title\": \"Arbitrary inputs are included in errors without any escaping in net/textproto\", \"affected\": [{\"vendor\": \"Go standard library\", \"product\": \"net/textproto\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"1.25.11\", \"versionType\": \"semver\"}, {\"status\": \"affected\", \"version\": \"1.26.0-0\", \"lessThan\": \"1.26.4\", \"versionType\": \"semver\"}], \"packageName\": \"net/textproto\", \"collectionURL\": \"https://pkg.go.dev\", \"defaultStatus\": \"unaffected\", \"programRoutines\": [{\"name\": \"parseCodeLine\"}, {\"name\": \"Reader.ReadCodeLine\"}, {\"name\": \"readMIMEHeader\"}, {\"name\": \"Error.Error\"}, {\"name\": \"Reader.ReadMIMEHeader\"}, {\"name\": \"Reader.ReadResponse\"}]}], \"references\": [{\"url\": \"https://go.dev/issue/79346\"}, {\"url\": \"https://go.dev/cl/777060\"}, {\"url\": \"https://groups.google.com/g/golang-announce/c/tKs3rmcBcKw\"}, {\"url\": \"https://pkg.go.dev/vuln/GO-2026-5039\"}], \"descriptions\": [{\"lang\": \"en\", \"value\": \"When returning errors, functions in the net/textproto package would include its input as part of the error. This might allow an attacker to inject misleading content to errors that are printed or logged.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"description\": \"CWE-532: Insertion of Sensitive Information into Log File\"}]}], \"providerMetadata\": {\"orgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"shortName\": \"Go\", \"dateUpdated\": \"2026-06-02T22:01:37.307Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-42507\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-06-03T19:04:45.361Z\", \"dateReserved\": \"2026-04-28T00:21:12.792Z\", \"assignerOrgId\": \"1bb62c36-49e3-4200-9d77-64a1400537cc\", \"datePublished\": \"2026-06-02T22:01:37.307Z\", \"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.