{"id":"CVE-2026-76077","title":"ASN1SCC: Stack buffer overflow and out-of-bounds read in XER tokenizer NT()","summary":"ASN1SCC is an open source ASN.1 compiler for embedded systems. Prior to 4.7.0.1, the XER tokenizer NT() in asn1crt/asn1crt_encoding_xer.c, which is reached by all XER decode paths, copies tag characters into a fixed char Value[100] field…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-120","CWE-125","CWE-787"],"vendor":"esa","product":"asn1scc","affected":["asn1scc < 4.7.0.1"],"published":"2026-11-05","updated":"2026-11-05","sourceUpdated":"2026-11-05T16:49:58.765Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-76077","references":[{"url":"https://github.com/esa/asn1scc/security/advisories/GHSA-38q3-fg5h-wwf9","label":"https://github.com/esa/asn1scc/security/advisories/GHSA-38q3-fg5h-wwf9"},{"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":"2026-11-05T22:38:31.408Z","slug":"CVE-2026-76077","body":"## Overview\n\nASN1SCC is an open source ASN.1 compiler for embedded systems. Prior to 4.7.0.1, the XER tokenizer NT() in asn1crt/asn1crt_encoding_xer.c, which is reached by all XER decode paths, copies tag characters into a fixed char Value[100] field without a length bound and reads input and lookahead bytes without checking the buffer count. A crafted XER message with an overlong tag can overwrite the tokenizer's stack frame, while a truncated tag or unterminated processing-instruction or comment sequence can read beyond the input and may cause a CPU spin. The flaws can disclose adjacent memory, corrupt stack data, crash or hang the decoder, and potentially permit code execution. 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":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}