{"cve":"CVE-2026-119197","nvd":{"published":"2026-10-29T20:17:30.907","modified":"2026-10-29T20:17:30.907","status":"Received","description":"pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.5, binary REAL decoding builds a large mantissa one octet at a time by shifting a growing integer and slicing the remaining byte string. Attacker-controlled ASN.1 includes a binary-encoded REAL with a large mantissa and reaches BER, CER, or DER decode(), with or without a schema containing REAL. RealPayloadDecoder.valueDecoder repeatedly performs a left shift, OR, and suffix copy for every mantissa octet, making decode time quadratic in mantissa length. A comparatively small REAL value can hold a decoding worker on one CPU core for seconds or longer and cause availability loss. This issue is fixed in version 0.6.5.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-407"],"references":["https://github.com/pyasn1/pyasn1/commit/ce3ec3390784780a530047e0e77be5ff457636a4","https://github.com/pyasn1/pyasn1/pull/132","https://github.com/pyasn1/pyasn1/releases/tag/v0.6.5","https://github.com/pyasn1/pyasn1/security/advisories/GHSA-mm57-4v3p-rchx"],"products":[],"source":"nvd","synced_at":"2026-10-29T20:32:52.295329973+00:00"},"epss":null,"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}