{"id":"CVE-2026-59884","state":"PUBLISHED","title":"pyasn1 BER/CER/DER decoder denial of service via unbounded long-form tag IDs","description":"pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4.","publishedAt":"2026-07-14T16:41:10.277Z","updatedAt":"2026-07-15T13:50:29.814Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["pyasn1 pyasn1"],"affected":[{"vendor":"pyasn1","product":"pyasn1","versions":[{"version":"< 0.6.4","status":"affected"}]}],"references":["https://github.com/pyasn1/pyasn1/security/advisories/GHSA-m4p7-r5rc-7g4j","https://github.com/pyasn1/pyasn1/commit/628e36ecbb5277a3f01572ce418ef54271b165a5","https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4"],"weaknesses":["CWE-400"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/59xxx/CVE-2026-59884.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-59884","state":"PUBLISHED","datePublished":"2026-07-14T16:41:10.277Z","dateUpdated":"2026-07-15T13:50:29.814Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-07T16:40:07.982Z"},"containers":{"cna":{"title":"pyasn1 BER/CER/DER decoder denial of service via unbounded long-form tag IDs","descriptions":[{"lang":"en","value":"pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4."}],"affected":[{"vendor":"pyasn1","product":"pyasn1","versions":[{"version":"< 0.6.4","status":"affected"}]}],"references":[{"url":"https://github.com/pyasn1/pyasn1/security/advisories/GHSA-m4p7-r5rc-7g4j","name":"https://github.com/pyasn1/pyasn1/security/advisories/GHSA-m4p7-r5rc-7g4j","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/pyasn1/pyasn1/commit/628e36ecbb5277a3f01572ce418ef54271b165a5","name":"https://github.com/pyasn1/pyasn1/commit/628e36ecbb5277a3f01572ce418ef54271b165a5","tags":["x_refsource_MISC"]},{"url":"https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4","name":"https://github.com/pyasn1/pyasn1/releases/tag/v0.6.4","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-14T16:41:10.277Z"},"source":{"advisory":"GHSA-m4p7-r5rc-7g4j","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-15T13:50:17.314569Z","id":"CVE-2026-59884","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-15T13:50:29.814Z"}}]}}}