Vulnerability-Lookup

GHSA-2755-2MM4-RM5C

Vulnerability from github – Published: 2026-04-22 21:32 – Updated: 2026-04-22 21:32

Details

http.cookies.Morsel.js_output() returns an inline snippet and only escapes " for JavaScript string context. It does not neutralize the HTML parser-sensitive sequence inside the generated script element. Mitigation base64-encodes the cookie value to disallow escaping using cookie value.

Severity ?

2.1 (Low)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-6019"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-150"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-22T20:16:42Z",
    "severity": "LOW"
  },
  "details": "http.cookies.Morsel.js_output() returns an inline \u003cscript\u003e snippet and only escapes \" for JavaScript string context. It does not neutralize the HTML parser-sensitive sequence \u003c/script\u003e inside the generated script element. Mitigation base64-encodes the cookie value to disallow escaping using cookie value.",
  "id": "GHSA-2755-2mm4-rm5c",
  "modified": "2026-04-22T21:32:11Z",
  "published": "2026-04-22T21:32:11Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6019"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/issues/90309"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/pull/148848"
    },
    {
      "type": "WEB",
      "url": "https://github.com/python/cpython/commit/76b3923d688c0efc580658476c5f525ec8735104"
    },
    {
      "type": "WEB",
      "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/IVNWGV2BBNC3RHQAFS22UP4DY56SAXX3"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/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",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-6019 (GCVE-0-2026-6019)

Vulnerability from cvelistv5 – Published: 2026-04-22 19:28 – Updated: 2026-04-22 20:02

Title

BaseCookie.js_output() does not neutralize embedded characters

Summary

http.cookies.Morsel.js_output() returns an inline <script> snippet and only escapes " for JavaScript string context. It does not neutralize the HTML parser-sensitive sequence </script> inside the generated script element. Mitigation base64-encodes the cookie value to disallow escaping using cookie value.

Severity ?

2.1 (Low)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

CWE

CWE-150 - Improper neutralization of escape, meta, or control sequences

Assigner

PSF

References

URL

Tags

	https://github.com/python/cpython/pull/148848	patch
	https://github.com/python/cpython/issues/90309	issue-tracking
	https://mail.python.org/archives/list/security-an…	vendor-advisory
	https://github.com/python/cpython/commit/76b3923d…	patch

Impacted products

	Vendor	Product	Version
	Python Software Foundation	CPython	Affected: 0 , < 3.15.0 (python)

Credits

oolongeya (https://github.com/komi22) Seth Larson (https://github.com/sethmlarson)

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-6019",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-22T20:02:17.071906Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-22T20:02:34.468Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "CPython",
          "repo": "https://github.com/python/cpython",
          "vendor": "Python Software Foundation",
          "versions": [
            {
              "lessThan": "3.15.0",
              "status": "affected",
              "version": "0",
              "versionType": "python"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "oolongeya (https://github.com/komi22)"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Seth Larson (https://github.com/sethmlarson)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003ccode\u003ehttp.cookies.Morsel.js_output()\u003c/code\u003e returns an inline \u003ccode\u003e\u0026lt;script\u0026gt;\u003c/code\u003e snippet and only escapes \u003ccode\u003e\"\u003c/code\u003e for JavaScript string context. It does not neutralize the HTML parser-sensitive sequence \u003ccode\u003e\u0026lt;/script\u0026gt;\u003c/code\u003e inside the generated script element. Mitigation base64-encodes the cookie value to disallow escaping using cookie value."
            }
          ],
          "value": "http.cookies.Morsel.js_output() returns an inline \u003cscript\u003e snippet and only escapes \" for JavaScript string context. It does not neutralize the HTML parser-sensitive sequence \u003c/script\u003e inside the generated script element. Mitigation base64-encodes the cookie value to disallow escaping using cookie value."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 2.1,
            "baseSeverity": "LOW",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "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:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
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            "vulnAvailabilityImpact": "NONE",
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            "vulnIntegrityImpact": "LOW",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
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      "providerMetadata": {
        "dateUpdated": "2026-04-22T19:43:15.838Z",
        "orgId": "28c92f92-d60d-412d-b760-e73465c3df22",
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      "references": [
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          "tags": [
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          "url": "https://github.com/python/cpython/pull/148848"
        },
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            "issue-tracking"
          ],
          "url": "https://github.com/python/cpython/issues/90309"
        },
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/IVNWGV2BBNC3RHQAFS22UP4DY56SAXX3/"
        },
        {
          "tags": [
            "patch"
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          "url": "https://github.com/python/cpython/commit/76b3923d688c0efc580658476c5f525ec8735104"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "BaseCookie.js_output() does not neutralize embedded characters",
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  },
  "cveMetadata": {
    "assignerOrgId": "28c92f92-d60d-412d-b760-e73465c3df22",
    "assignerShortName": "PSF",
    "cveId": "CVE-2026-6019",
    "datePublished": "2026-04-22T19:28:08.720Z",
    "dateReserved": "2026-04-09T15:35:00.668Z",
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}

Sightings

Author	Source	Type	Date

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.

Action not permitted

GHSA-2755-2MM4-RM5C

CVE-2026-6019 (GCVE-0-2026-6019)

Tags

Sightings

Nomenclature