{"id":"CVE-2026-27026","state":"PUBLISHED","title":"pypdf possibly has long runtimes for malformed FlateDecode streams","description":"pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1.","publishedAt":"2026-02-20T21:12:33.537Z","updatedAt":"2026-02-24T18:47:02.304Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["py-pdf pypdf"],"affected":[{"vendor":"py-pdf","product":"pypdf","versions":[{"version":"< 6.7.1","status":"affected"}]}],"references":["https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h","https://github.com/py-pdf/pypdf/pull/3644","https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016","https://github.com/py-pdf/pypdf/releases/tag/6.7.1"],"weaknesses":["CWE-770"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/27xxx/CVE-2026-27026.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27026","state":"PUBLISHED","datePublished":"2026-02-20T21:12:33.537Z","dateUpdated":"2026-02-24T18:47:02.304Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-17T03:08:23.491Z"},"containers":{"cna":{"title":"pypdf possibly has long runtimes for malformed FlateDecode streams","descriptions":[{"lang":"en","value":"pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1."}],"affected":[{"vendor":"py-pdf","product":"pypdf","versions":[{"version":"< 6.7.1","status":"affected"}]}],"references":[{"url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h","name":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-9mvc-8737-8j8h","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/py-pdf/pypdf/pull/3644","name":"https://github.com/py-pdf/pypdf/pull/3644","tags":["x_refsource_MISC"]},{"url":"https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016","name":"https://github.com/py-pdf/pypdf/commit/7905842d833f899f1d3228af7e7467ad80277016","tags":["x_refsource_MISC"]},{"url":"https://github.com/py-pdf/pypdf/releases/tag/6.7.1","name":"https://github.com/py-pdf/pypdf/releases/tag/6.7.1","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"LOCAL","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":6.9,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-02-20T21:12:33.537Z"},"source":{"advisory":"GHSA-9mvc-8737-8j8h","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-02-24T18:46:44.502341Z","id":"CVE-2026-27026","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-02-24T18:47:02.304Z"}}]}}}