{"api_version":"1","generated_at":"2026-07-23T13:30:19+00:00","cve":"CVE-2026-3644","urls":{"html":"https://cve.report/CVE-2026-3644","api":"https://cve.report/api/cve/CVE-2026-3644.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-3644","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-3644"},"summary":{"title":"Incomplete control character validation in http.cookies","description":"The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output().","state":"PUBLISHED","assigner":"PSF","published_at":"2026-03-16 18:16:09","updated_at":"2026-06-30 16:16:50"},"problem_types":["CWE-20","CWE-116","CWE-20 CWE-20 Improper Input Validation","CWE-116 CWE-116 Improper Encoding or Escaping of Output"],"metrics":[{"version":"4.0","source":"cna@python.org","type":"Secondary","score":"6","severity":"MEDIUM","vector":"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","data":{"version":"4.0","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","baseScore":6,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","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"}},{"version":"4.0","source":"CNA","type":"CVSS","score":"6","severity":"MEDIUM","vector":"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","data":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6,"baseSeverity":"MEDIUM","exploitMaturity":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"}},{"version":"3.1","source":"nvd@nist.gov","type":"Primary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"}}],"references":[{"url":"https://mail.python.org/archives/list/security-announce@python.org/thread/H6CADMBCDRFGWCMOXWUIHFJNV43GABJ7/","name":"https://mail.python.org/archives/list/security-announce@python.org/thread/H6CADMBCDRFGWCMOXWUIHFJNV43GABJ7/","refsource":"cna@python.org","tags":["Third Party Advisory"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/python/cpython/issues/145599","name":"https://github.com/python/cpython/issues/145599","refsource":"cna@python.org","tags":["Issue Tracking"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590dd","name":"https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590dd","refsource":"cna@python.org","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/python/cpython/commit/dae4b1a21f8df4570e30986affd61bbe4ade4cef","name":"https://github.com/python/cpython/commit/dae4b1a21f8df4570e30986affd61bbe4ade4cef","refsource":"cna@python.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979dd","name":"https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979dd","refsource":"cna@python.org","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/python/cpython/commit/556aa098e738b127c714866f819b4abe2f7593d8","name":"https://github.com/python/cpython/commit/556aa098e738b127c714866f819b4abe2f7593d8","refsource":"cna@python.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/python/cpython/pull/145600","name":"https://github.com/python/cpython/pull/145600","refsource":"cna@python.org","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4","name":"https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4","refsource":"cna@python.org","tags":["Patch"],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-3644","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-3644","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Python Software Foundation","product":"CPython","version":"affected 3.13.13 python","platforms":[]},{"source":"CNA","vendor":"Python Software Foundation","product":"CPython","version":"affected 3.14.0 3.14.4 python","platforms":[]},{"source":"CNA","vendor":"Python Software Foundation","product":"CPython","version":"affected 3.15.0a1 3.15.0a8 python","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[{"source":"CNA","value":"Stan Ulbrych","lang":"en"},{"source":"CNA","value":"Stan Ulbrych","lang":"en"},{"source":"CNA","value":"Victor Stinner","lang":"en"},{"source":"CNA","value":"Seth Larson","lang":"en"},{"source":"CNA","value":"Vyom Yadav","lang":"en"}],"nvd_cpes":[{"cve_year":"2026","cve_id":"3644","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"a","cpe4":"python","cpe5":"python","cpe6":"*","cpe7":"*","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"}],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2026-3644","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-03-16T18:25:27.051552Z","version":"2.0.3"},"type":"ssvc"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","description":"CWE-20 Improper Input Validation","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-116","description":"CWE-116 Improper Encoding or Escaping of Output","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-03-16T18:25:55.021Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"}],"cna":{"affected":[{"defaultStatus":"unaffected","modules":["http.cookies"],"product":"CPython","repo":"https://github.com/python/cpython","vendor":"Python Software Foundation","versions":[{"lessThan":"3.13.13","status":"affected","version":"0","versionType":"python"},{"lessThan":"3.14.4","status":"affected","version":"3.14.0","versionType":"python"},{"lessThan":"3.15.0a8","status":"affected","version":"3.15.0a1","versionType":"python"}]}],"credits":[{"lang":"en","type":"coordinator","value":"Stan Ulbrych"},{"lang":"en","type":"remediation developer","value":"Stan Ulbrych"},{"lang":"en","type":"remediation reviewer","value":"Victor Stinner"},{"lang":"en","type":"remediation reviewer","value":"Seth Larson"},{"lang":"en","type":"reporter","value":"Vyom Yadav"}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output()."}],"value":"The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output()."}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"PRESENT","attackVector":"NETWORK","baseScore":6,"baseSeverity":"MEDIUM","exploitMaturity":"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","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"providerMetadata":{"dateUpdated":"2026-06-30T15:11:21.792Z","orgId":"28c92f92-d60d-412d-b760-e73465c3df22","shortName":"PSF"},"references":[{"tags":["vendor-advisory"],"url":"https://mail.python.org/archives/list/security-announce@python.org/thread/H6CADMBCDRFGWCMOXWUIHFJNV43GABJ7/"},{"tags":["patch"],"url":"https://github.com/python/cpython/commit/57e88c1cf95e1481b94ae57abe1010469d47a6b4"},{"tags":["issue-tracking"],"url":"https://github.com/python/cpython/issues/145599"},{"tags":["patch"],"url":"https://github.com/python/cpython/pull/145600"},{"tags":["patch"],"url":"https://github.com/python/cpython/commit/62ceb396fcbe69da1ded3702de586f4072b590dd"},{"tags":["patch"],"url":"https://github.com/python/cpython/commit/d16ecc6c3626f0e2cc8f08c309c83934e8a979dd"},{"tags":["patch"],"url":"https://github.com/python/cpython/commit/556aa098e738b127c714866f819b4abe2f7593d8"},{"tags":["patch"],"url":"https://github.com/python/cpython/commit/dae4b1a21f8df4570e30986affd61bbe4ade4cef"}],"source":{"discovery":"UNKNOWN"},"title":"Incomplete control character validation in http.cookies","x_generator":{"engine":"Vulnogram 1.0.0"}}},"cveMetadata":{"assignerOrgId":"28c92f92-d60d-412d-b760-e73465c3df22","assignerShortName":"PSF","cveId":"CVE-2026-3644","datePublished":"2026-03-16T17:37:31.344Z","dateReserved":"2026-03-06T16:13:09.289Z","dateUpdated":"2026-06-30T15:11:21.792Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-03-16 18:16:09","lastModifiedDate":"2026-06-30 16:16:50","problem_types":["CWE-20","CWE-116","CWE-20 CWE-20 Improper Input Validation","CWE-116 CWE-116 Improper Encoding or Escaping of Output"],"metrics":{"cvssMetricV40":[{"source":"cna@python.org","type":"Secondary","cvssData":{"version":"4.0","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","baseScore":6,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","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"}}],"cvssMetricV31":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"NONE"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-03-16T18:25:27.051552Z","id":"CVE-2026-3644","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:*:*:*:*:*:*:*:*","versionEndExcluding":"3.13.13","matchCriteriaId":"74460139-CF2A-457B-82B4-7B655FB576B1"},{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14.0","versionEndExcluding":"3.14.4","matchCriteriaId":"AA3B34C3-1E02-4674-8370-0DD4D24DBE58"},{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:3.15.0:alpha1:*:*:*:*:*:*","matchCriteriaId":"A3327507-0B1D-4F28-A983-D07A2C8A7696"},{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:3.15.0:alpha2:*:*:*:*:*:*","matchCriteriaId":"C8AF17F1-A27F-4C98-BA5A-B4319710E8D1"},{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:3.15.0:alpha3:*:*:*:*:*:*","matchCriteriaId":"24CF56B0-2F4E-42A2-B655-F493AA0A4815"},{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:3.15.0:alpha4:*:*:*:*:*:*","matchCriteriaId":"7184ABBA-B100-489E-B5C1-1C9EEC0546CA"},{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:3.15.0:alpha5:*:*:*:*:*:*","matchCriteriaId":"B6D4181B-3E1B-499B-AAB1-50868A6A6AD3"},{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:3.15.0:alpha6:*:*:*:*:*:*","matchCriteriaId":"A52F6DD2-717D-4E8C-8DB7-00890BC1ABAE"},{"vulnerable":true,"criteria":"cpe:2.3:a:python:python:3.15.0:alpha7:*:*:*:*:*:*","matchCriteriaId":"8C46C55C-801E-4F86-B669-8E6A12B4AB6F"}]}]}]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"3644","Ordinal":"1","Title":"Incomplete control character validation in http.cookies","CVE":"CVE-2026-3644","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"3644","Ordinal":"1","NoteData":"The fix for CVE-2026-0672, which rejected control characters in http.cookies.Morsel, was incomplete. The Morsel.update(), |= operator, and unpickling paths were not patched, allowing control characters to bypass input validation. Additionally, BaseCookie.js_output() lacked the output validation applied to BaseCookie.output().","Type":"Description","Title":"Incomplete control character validation in http.cookies"}]}}}