{"id":"CVE-2026-75615","title":"ASN1SCC: Out-of-bounds read via unvalidated character index in ASN.1 string decoders","summary":"ASN1SCC is an open source ASN.1 compiler for embedded systems. Prior to 4.7.0.1, the ACN runtime function Acn_Dec_String_CharIndex_private in asn1crt/asn1crt_encoding_acn.c and the generated uPER decoder InternalItem_string_with_alpha_de…","severity":"medium","cvss":5.3,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","cvssSource":"cna","cwe":["CWE-125","CWE-129"],"vendor":"esa","product":"asn1scc","affected":["asn1scc < 4.7.0.1"],"published":"2026-11-05","updated":"2026-11-05","sourceUpdated":"2026-11-05T16:49:20.422Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-75615","references":[{"url":"https://github.com/esa/asn1scc/security/advisories/GHSA-234q-m7gr-pcf8","label":"https://github.com/esa/asn1scc/security/advisories/GHSA-234q-m7gr-pcf8"},{"url":"https://github.com/esa/asn1scc/commit/fe6ab763bc60d8a2def4104c15414809b45fffd9","label":"https://github.com/esa/asn1scc/commit/fe6ab763bc60d8a2def4104c15414809b45fffd9"},{"url":"https://github.com/esa/asn1scc/releases/tag/4.7.0.1","label":"https://github.com/esa/asn1scc/releases/tag/4.7.0.1"}],"tags":["cve.org"],"ingestedAt":"2026-11-05T22:38:31.411Z","slug":"CVE-2026-75615","body":"## Overview\n\nASN1SCC is an open source ASN.1 compiler for embedded systems. Prior to 4.7.0.1, the ACN runtime function Acn_Dec_String_CharIndex_private in asn1crt/asn1crt_encoding_acn.c and the generated uPER decoder InternalItem_string_with_alpha_decode in StgC/uper_c.stg do not validate a decoded character index before reading allowedCharSet. For string alphabets whose size is not a power of two, a crafted message can select an unused encoded index, read a small bounded window of adjacent static program constants, and return the byte as a successfully decoded character. The full 128-character IA5String alphabet is not affected. This issue is fixed in version 4.7.0.1.\n\n## Affected\n\n- `asn1scc < 4.7.0.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":29,"depthScoreParts":{"impact":29.2,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}