---
id: CVE-2026-75614
title: >-
  ASN1SCC: Out-of-bounds write in BitStream_DecodeConstraintWholeNumber
  (uPER/ACN)
summary: >-
  ASN1SCC is an open source ASN.1 compiler for embedded systems. Prior to
  4.7.0.1, BitStream_DecodeConstraintWholeNumber in asn1crt/asn1crt_encoding.c
  reads enough bits for a constrained integer but does not reject values above
  the declare…
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-129
  - CWE-787
vendor: esa
product: asn1scc
affected:
  - asn1scc < 4.7.0.1
ssvc:
  exploitation: poc
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-11-05T18:25:12.643188Z'
exploitAvailable: true
published: '2026-11-05'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T18:26:01.514Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-75614'
references:
  - url: 'https://github.com/esa/asn1scc/security/advisories/GHSA-825c-7h77-2jjq'
    label: 'https://github.com/esa/asn1scc/security/advisories/GHSA-825c-7h77-2jjq'
  - 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
  - exploit-available
ingestedAt: '2026-11-05T22:38:31.469Z'
---

## Overview

ASN1SCC is an open source ASN.1 compiler for embedded systems. Prior to 4.7.0.1, BitStream_DecodeConstraintWholeNumber in asn1crt/asn1crt_encoding.c reads enough bits for a constrained integer but does not reject values above the declared range when the encoded range is not a power of two. Generated uPER and ACN decoders for variable-size SEQUENCE OF, OCTET STRING, BIT STRING, and string values use the invalid result as a loop or copy length, so a crafted over-range size field can write beyond a destination buffer. Decoding untrusted affected data can corrupt heap or stack memory, cause a crash, or potentially permit code execution. This issue is fixed in version 4.7.0.1.

## Affected

- `asn1scc < 4.7.0.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.