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_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.
History

Thu, 12 Nov 2026 01:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 06 Nov 2026 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Esa
Esa asn1scc
Vendors & Products Esa
Esa asn1scc

Fri, 06 Nov 2026 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Thu, 05 Nov 2026 17:00:00 +0000

Type Values Removed Values Added
Description 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_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.
Title ASN1SCC: Out-of-bounds read via unvalidated character index in ASN.1 string decoders
Weaknesses CWE-125
CWE-129
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-11-05T16:49:20.422Z

Updated: 2026-11-09T22:21:47.449Z

Reserved: 2026-08-17T23:49:03.451Z

Link: CVE-2026-75615

cve-icon Vulnrichment

Updated: 2026-11-09T22:21:42.838Z

cve-icon NVD

Status : Received

Published: 2026-11-05T17:18:20.663

Modified: 2026-11-09T23:17:26.103

Link: CVE-2026-75615

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-11-05T16:49:20Z

Links: CVE-2026-75615 - Bugzilla