{"cve":"CVE-2026-34180","nvd":{"published":"2026-06-09T17:17:04.600","modified":"2026-07-23T08:10:00.137","status":"Analyzed","description":"Issue summary: Parsing a crafted DER-encoded ASN.1 structure with a primitive\nelement whose content exceeds 2 gigabytes in length may cause a heap buffer\nover-read on 64-bit Unix and Unix-like platforms.\n\nImpact summary: The heap buffer over-read may crash the application (Denial of\nService) or to load into the decoded ASN.1 object contents of memory beyond the\nend of the input buffer.  More typically such ASN.1 elements would instead be\ntruncated.\n\nAn integer truncation in OpenSSL's ASN.1 decoder causes the content length of\nan ASN.1 primitive element to be mishandled when it exceeds 2 gigabytes. In the\nworst case the truncated length is treated as a request to scan the binary\ncontent for a terminating zero byte, possibly causing OpenSSL to read either\nless than or beyond the end of the allocated buffer.\n\nApplications that pass attacker-supplied data to d2i_X509(), d2i_PKCS7(), or\nany other d2i_* decoding function are affected. OpenSSL's own command-line\ntools are not vulnerable, as data read through the BIO layer is checked before\nit reaches the affected code. The issue only affects 64-bit Unix and Unix-like\nplatforms; 32-bit platforms and 64-bit Windows are not affected.\n\nThe FIPS modules in 4.0, 3.6, 3.5, 3.4 and 3.0 are not affected by this issue,\nas the affected code is outside the OpenSSL FIPS module boundary.","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-125"],"references":["https://github.com/openssl/openssl/commit/1c6908e4fa5fa568752221d8eaf561a809751e5d","https://github.com/openssl/openssl/commit/cbe418ae978539cf14a398a207dba834c0e93e83","https://github.com/openssl/openssl/commit/d93853c42110d6319e3df07842b488cb9f7ac5ff","https://github.com/openssl/openssl/commit/da5d62af75f69d6fbf7803743d7c56ac75461e43","https://github.com/openssl/openssl/commit/f696c73c3e61b8c502d040af62e690c060908a16"],"products":["openssl:openssl"],"source":"nvd","synced_at":"2026-10-19T22:38:48.522727527+00:00"},"epss":{"cve":"CVE-2026-34180","score":0.01025,"percentile":0.63597,"date":"2026-10-31"},"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."]}