CVE-2026-1502 (GCVE-0-2026-1502)

Vulnerability from cvelistv5 – Published: 2026-04-10 17:54 – Updated: 2026-05-12 13:24
VLAI
Title
HTTP client proxy tunnel headers not validated for CR/LF
Summary
CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.
Severity
5.7 (Medium)
CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CWE
  • CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')
Assigner
PSF
References
Impacted products
Vendor Product Version
Python Software Foundation CPython Affected: 0 , < 3.14.5rc1 (python)
Affected: 3.15.0a1 , < 3.15.0b1 (python)
Create a notification for this product.
Credits
senseicat Seth Larson
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2026-04-11T04:39:26.099Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "url": "http://www.openwall.com/lists/oss-security/2026/04/11/4"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-1502",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-13T16:08:30.380828Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "cweId": "CWE-93",
                "description": "CWE-93 Improper Neutralization of CRLF Sequences (\u0027CRLF Injection\u0027)",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-10T20:05:37.267Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageName": "http.client",
          "product": "CPython",
          "repo": "https://github.com/python/cpython",
          "vendor": "Python Software Foundation",
          "versions": [
            {
              "lessThan": "3.14.5rc1",
              "status": "affected",
              "version": "0",
              "versionType": "python"
            },
            {
              "lessThan": "3.15.0b1",
              "status": "affected",
              "version": "3.15.0a1",
              "versionType": "python"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "senseicat"
        },
        {
          "lang": "en",
          "type": "coordinator",
          "value": "Seth Larson"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "type": "text/html",
              "value": "CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host."
            }
          ],
          "value": "CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 5.7,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "HIGH",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-12T13:24:35.847Z",
        "orgId": "28c92f92-d60d-412d-b760-e73465c3df22",
        "shortName": "PSF"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/python/cpython/pull/146212"
        },
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://github.com/python/cpython/issues/146211"
        },
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://mail.python.org/archives/list/security-announce@python.org/thread/2IVPAEQWUJBCTQZEJEVTYCIKSMQPGRZ3/"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/python/cpython/commit/05ed7ce7ae9e17c23a04085b2539fe6d6d3cef69"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/python/cpython/commit/b1cf9016335cb637c5a425032e8274a224f4b2ed"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "HTTP client proxy tunnel headers not validated for CR/LF",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "28c92f92-d60d-412d-b760-e73465c3df22",
    "assignerShortName": "PSF",
    "cveId": "CVE-2026-1502",
    "datePublished": "2026-04-10T17:54:44.121Z",
    "dateReserved": "2026-01-27T19:10:37.711Z",
    "dateUpdated": "2026-05-12T13:24:35.847Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-1502",
      "date": "2026-05-25",
      "epss": "0.00024",
      "percentile": "0.06952"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-1502\",\"sourceIdentifier\":\"cna@python.org\",\"published\":\"2026-04-10T18:16:40.970\",\"lastModified\":\"2026-05-10T21:16:28.247\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.\"}],\"metrics\":{\"cvssMetricV40\":[{\"source\":\"cna@python.org\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"4.0\",\"vectorString\":\"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/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\",\"baseScore\":5.7,\"baseSeverity\":\"MEDIUM\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"attackRequirements\":\"PRESENT\",\"privilegesRequired\":\"HIGH\",\"userInteraction\":\"PASSIVE\",\"vulnConfidentialityImpact\":\"NONE\",\"vulnIntegrityImpact\":\"HIGH\",\"vulnAvailabilityImpact\":\"NONE\",\"subConfidentialityImpact\":\"NONE\",\"subIntegrityImpact\":\"NONE\",\"subAvailabilityImpact\":\"NONE\",\"exploitMaturity\":\"NOT_DEFINED\",\"confidentialityRequirement\":\"NOT_DEFINED\",\"integrityRequirement\":\"NOT_DEFINED\",\"availabilityRequirement\":\"NOT_DEFINED\",\"modifiedAttackVector\":\"NOT_DEFINED\",\"modifiedAttackComplexity\":\"NOT_DEFINED\",\"modifiedAttackRequirements\":\"NOT_DEFINED\",\"modifiedPrivilegesRequired\":\"NOT_DEFINED\",\"modifiedUserInteraction\":\"NOT_DEFINED\",\"modifiedVulnConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedVulnIntegrityImpact\":\"NOT_DEFINED\",\"modifiedVulnAvailabilityImpact\":\"NOT_DEFINED\",\"modifiedSubConfidentialityImpact\":\"NOT_DEFINED\",\"modifiedSubIntegrityImpact\":\"NOT_DEFINED\",\"modifiedSubAvailabilityImpact\":\"NOT_DEFINED\",\"Safety\":\"NOT_DEFINED\",\"Automatable\":\"NOT_DEFINED\",\"Recovery\":\"NOT_DEFINED\",\"valueDensity\":\"NOT_DEFINED\",\"vulnerabilityResponseEffort\":\"NOT_DEFINED\",\"providerUrgency\":\"NOT_DEFINED\"}}]},\"weaknesses\":[{\"source\":\"134c704f-9b21-4f2e-91b3-4a467353bcc0\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-93\"}]}],\"references\":[{\"url\":\"https://github.com/python/cpython/commit/05ed7ce7ae9e17c23a04085b2539fe6d6d3cef69\",\"source\":\"cna@python.org\"},{\"url\":\"https://github.com/python/cpython/commit/b1cf9016335cb637c5a425032e8274a224f4b2ed\",\"source\":\"cna@python.org\"},{\"url\":\"https://github.com/python/cpython/issues/146211\",\"source\":\"cna@python.org\"},{\"url\":\"https://github.com/python/cpython/pull/146212\",\"source\":\"cna@python.org\"},{\"url\":\"https://mail.python.org/archives/list/security-announce@python.org/thread/2IVPAEQWUJBCTQZEJEVTYCIKSMQPGRZ3/\",\"source\":\"cna@python.org\"},{\"url\":\"http://www.openwall.com/lists/oss-security/2026/04/11/4\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\"}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CVE Program Container\", \"references\": [{\"url\": \"http://www.openwall.com/lists/oss-security/2026/04/11/4\"}], \"providerMetadata\": {\"orgId\": \"af854a3a-2127-422b-91ae-364da2661108\", \"shortName\": \"CVE\", \"dateUpdated\": \"2026-04-11T04:39:26.099Z\"}}, {\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-1502\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-04-13T16:08:30.380828Z\"}}}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-93\", \"description\": \"CWE-93 Improper Neutralization of CRLF Sequences (\u0027CRLF Injection\u0027)\"}]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-04-13T16:08:38.688Z\"}}], \"cna\": {\"title\": \"HTTP client proxy tunnel headers not validated for CR/LF\", \"source\": {\"discovery\": \"UNKNOWN\"}, \"credits\": [{\"lang\": \"en\", \"type\": \"reporter\", \"value\": \"senseicat\"}, {\"lang\": \"en\", \"type\": \"coordinator\", \"value\": \"Seth Larson\"}], \"metrics\": [{\"format\": \"CVSS\", \"cvssV4_0\": {\"Safety\": \"NOT_DEFINED\", \"version\": \"4.0\", \"Recovery\": \"NOT_DEFINED\", \"baseScore\": 5.7, \"Automatable\": \"NOT_DEFINED\", \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"valueDensity\": \"NOT_DEFINED\", \"vectorString\": \"CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N\", \"exploitMaturity\": \"NOT_DEFINED\", \"providerUrgency\": \"NOT_DEFINED\", \"userInteraction\": \"PASSIVE\", \"attackComplexity\": \"LOW\", \"attackRequirements\": \"PRESENT\", \"privilegesRequired\": \"HIGH\", \"subIntegrityImpact\": \"NONE\", \"vulnIntegrityImpact\": \"HIGH\", \"subAvailabilityImpact\": \"NONE\", \"vulnAvailabilityImpact\": \"NONE\", \"subConfidentialityImpact\": \"NONE\", \"vulnConfidentialityImpact\": \"NONE\", \"vulnerabilityResponseEffort\": \"NOT_DEFINED\"}, \"scenarios\": [{\"lang\": \"en\", \"value\": \"GENERAL\"}]}], \"affected\": [{\"repo\": \"https://github.com/python/cpython\", \"vendor\": \"Python Software Foundation\", \"product\": \"CPython\", \"versions\": [{\"status\": \"affected\", \"version\": \"0\", \"lessThan\": \"3.14.5rc1\", \"versionType\": \"python\"}, {\"status\": \"affected\", \"version\": \"3.15.0a1\", \"lessThan\": \"3.15.0b1\", \"versionType\": \"python\"}], \"packageName\": \"http.client\", \"defaultStatus\": \"unaffected\"}], \"references\": [{\"url\": \"https://github.com/python/cpython/pull/146212\", \"tags\": [\"patch\"]}, {\"url\": \"https://github.com/python/cpython/issues/146211\", \"tags\": [\"issue-tracking\"]}, {\"url\": \"https://mail.python.org/archives/list/security-announce@python.org/thread/2IVPAEQWUJBCTQZEJEVTYCIKSMQPGRZ3/\", \"tags\": [\"vendor-advisory\"]}, {\"url\": \"https://github.com/python/cpython/commit/05ed7ce7ae9e17c23a04085b2539fe6d6d3cef69\", \"tags\": [\"patch\"]}, {\"url\": \"https://github.com/python/cpython/commit/b1cf9016335cb637c5a425032e8274a224f4b2ed\", \"tags\": [\"patch\"]}], \"x_generator\": {\"engine\": \"cvelib 1.8.0\"}, \"descriptions\": [{\"lang\": \"en\", \"value\": \"CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"CR/LF bytes were not rejected by HTTP client proxy tunnel headers or host.\"}]}], \"providerMetadata\": {\"orgId\": \"28c92f92-d60d-412d-b760-e73465c3df22\", \"shortName\": \"PSF\", \"dateUpdated\": \"2026-05-12T13:24:35.847Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-1502\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-05-12T13:24:35.847Z\", \"dateReserved\": \"2026-01-27T19:10:37.711Z\", \"assignerOrgId\": \"28c92f92-d60d-412d-b760-e73465c3df22\", \"datePublished\": \"2026-04-10T17:54:44.121Z\", \"assignerShortName\": \"PSF\"}",
      "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.