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CVE-2026-87864

Full vulnerability record from the local CVENow database.

Description

Enabling `CURLOPT_CRLF` causes curl to advertise the raw input byte count in the `IMAP APPEND {N}` literal while transmitting line-ending expanded data. The server reads only $N$ bytes for the payload, causing the remaining overflow bytes to be interpreted and executed as pipelined IMAP commands within the authenticated session.

Severity
HIGH
CVSS score
8.1 (v3.1)
Vulnerability status
Awaiting Analysis
Source identifier
2499f714-1537-4658-8207-48ae4bb9eae9
Published
2026-10-20 21:17:20.497000
Last modified
2026-10-30 12:16:46.137000
View original CVE JSON
{
  "id": "CVE-2026-87864",
  "sourceIdentifier": "2499f714-1537-4658-8207-48ae4bb9eae9",
  "published": "2026-10-20T21:17:20.497",
  "lastModified": "2026-10-30T12:16:46.137",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Enabling `CURLOPT_CRLF` causes curl to advertise the raw input byte count in\nthe `IMAP APPEND {N}` literal while transmitting line-ending expanded data.\nThe server reads only $N$ bytes for the payload, causing the remaining\noverflow bytes to be interpreted and executed as pipelined IMAP commands\nwithin the authenticated session."
    }
  ],
  "affected": [
    {
      "source": "2499f714-1537-4658-8207-48ae4bb9eae9",
      "affectedData": [
        {
          "vendor": "curl",
          "product": "curl",
          "defaultStatus": "unaffected",
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              "version": "8.21.0",
              "lessThanOrEqual": "8.21.0",
              "versionType": "semver",
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              "version": "8.20.0",
              "lessThanOrEqual": "8.20.0",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "8.19.0",
              "lessThanOrEqual": "8.19.0",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "8.18.0",
              "lessThanOrEqual": "8.18.0",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "8.17.0",
              "lessThanOrEqual": "8.17.0",
              "versionType": "semver",
              "status": "affected"
            },
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              "version": "8.16.0",
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              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "8.15.0",
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              "versionType": "semver",
              "status": "affected"
            },
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              "version": "8.14.1",
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              "status": "affected"
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              "version": "8.8.0",
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              "version": "8.7.1",
              "lessThanOrEqual": "8.7.1",
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              "status": "affected"
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              "version": "8.7.0",
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              "version": "8.6.0",
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              "status": "affected"
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              "version": "8.5.0",
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              "status": "affected"
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              "version": "8.2.0",
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              "version": "8.0.0",
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              "version": "7.88.1",
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              "status": "affected"
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            {
              "version": "7.88.0",
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              "version": "7.87.0",
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              "version": "7.86.0",
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              "lessThanOrEqual": "7.81.0",
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              "version": "7.65.3",
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              "version": "7.64.1",
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              "version": "7.54.0",
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              "status": "affected"
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              "version": "7.53.1",
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    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 8.1,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-30T12:00:41.170459Z",
          "id": "CVE-2026-87864",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-130"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://curl.se/docs/CVE-2026-87864.html",
      "source": "2499f714-1537-4658-8207-48ae4bb9eae9"
    },
    {
      "url": "https://curl.se/docs/CVE-2026-87864.json",
      "source": "2499f714-1537-4658-8207-48ae4bb9eae9"
    },
    {
      "url": "https://hackerone.com/reports/3972403",
      "source": "2499f714-1537-4658-8207-48ae4bb9eae9"
    },
    {
      "url": "https://hackerone.com/reports/3972403",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"
    }
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}