FKIE_CVE-2026-1299

Vulnerability from fkie_nvd - Published: 2026-01-23 17:16 - Updated: 2026-02-13 17:16
Severity ?
6.0 (Medium) - CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N
Summary
The email module, specifically the "BytesGenerator" class, didn’t properly quote newlines for email headers when serializing an email message allowing for header injection when an email is serialized. This is only applicable if using "LiteralHeader" writing headers that don't respect email folding rules, the new behavior will reject the incorrectly folded headers in "BytesGenerator".
References
cna@python.orghttps://cve.org/CVERecord?id=CVE-2024-6923
cna@python.orghttps://github.com/python/cpython/commit/052e55e7d44718fe46cbba0ca995cb8fcc359413
cna@python.orghttps://github.com/python/cpython/commit/0a925ab591c45d6638f37b5e57796f36fa0e56d8
cna@python.orghttps://github.com/python/cpython/commit/7877fe424415bc4a13045e62a90a7277413d8cb9
cna@python.orghttps://github.com/python/cpython/commit/842ce19a0c0b58d61591e8f6a708c38db1fb94e4
cna@python.orghttps://github.com/python/cpython/commit/8cdf6204f4ae821f32993f8fc6bad0d318f95f36
cna@python.orghttps://github.com/python/cpython/commit/e417f05ad77a4c30ddc07f99e90fc0cef43e831a
cna@python.orghttps://github.com/python/cpython/issues/144125
cna@python.orghttps://github.com/python/cpython/pull/144126
cna@python.orghttps://mail.python.org/archives/list/security-announce@python.org/thread/6ZZULGALJTITEAGEXLDJE2C6FORDXPBT/
Impacted products
Vendor Product Version
To clipboard 

{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The \nemail module, specifically the \"BytesGenerator\" class, didn\u2019t properly quote newlines for email headers when \nserializing an email message allowing for header injection when an email\n is serialized. This is only applicable if using \"LiteralHeader\" writing headers that don\u0027t respect email folding rules, the new behavior will reject the incorrectly folded headers in \"BytesGenerator\"."
    },
    {
      "lang": "es",
      "value": "El m\u00f3dulo de correo electr\u00f3nico, espec\u00edficamente la clase \u0027BytesGenerator\u0027, no escapaba correctamente los saltos de l\u00ednea para los encabezados de correo electr\u00f3nico al serializar un mensaje de correo electr\u00f3nico, lo que permit\u00eda la inyecci\u00f3n de encabezados cuando se serializa un correo electr\u00f3nico. Esto solo es aplicable si se utiliza \u0027LiteralHeader\u0027 para escribir encabezados que no respetan las reglas de plegado de correo electr\u00f3nico; el nuevo comportamiento rechazar\u00e1 los encabezados plegados incorrectamente en \u0027BytesGenerator\u0027."
    }
  ],
  "id": "CVE-2026-1299",
  "lastModified": "2026-02-13T17:16:12.943",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 6.0,
          "baseSeverity": "MEDIUM",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "LOW",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "cna@python.org",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-01-23T17:16:12.977",
  "references": [
    {
      "source": "cna@python.org",
      "url": "https://cve.org/CVERecord?id=CVE-2024-6923"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/052e55e7d44718fe46cbba0ca995cb8fcc359413"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/0a925ab591c45d6638f37b5e57796f36fa0e56d8"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/7877fe424415bc4a13045e62a90a7277413d8cb9"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/842ce19a0c0b58d61591e8f6a708c38db1fb94e4"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/8cdf6204f4ae821f32993f8fc6bad0d318f95f36"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/commit/e417f05ad77a4c30ddc07f99e90fc0cef43e831a"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/issues/144125"
    },
    {
      "source": "cna@python.org",
      "url": "https://github.com/python/cpython/pull/144126"
    },
    {
      "source": "cna@python.org",
      "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/6ZZULGALJTITEAGEXLDJE2C6FORDXPBT/"
    }
  ],
  "sourceIdentifier": "cna@python.org",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-93"
        }
      ],
      "source": "cna@python.org",
      "type": "Secondary"
    }
  ]
}


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