---
id: CVE-2026-62298
title: 'asn1c: ASAN crash with decode of open types'
summary: >-
  mouse07410/asn1c is an ASN.1 compiler. Prior to 1.2.5, `OPEN TYPE` decoding
  can dereference an unallocated member pointer and crash the consuming program.
  `OPEN_TYPE_aper_get` in `OPEN_TYPE_aper.c`, `OPEN_TYPE_ber_get` in
  `OPEN_TYPE_ber.…
severity: none
cvss: 0
cvssVector: 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N'
cvssSource: cna
cwe:
  - CWE-476
vendor: mouse07410
product: asn1c
affected:
  - asn1c < 1.2.5
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-10-30T21:18:14.628986Z'
published: '2026-10-30'
updated: '2026-10-30'
sourceUpdated: '2026-10-30T22:15:29.845Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-62298'
references:
  - url: >-
      https://github.com/mouse07410/asn1c/security/advisories/GHSA-rcj5-gcvg-x796
    label: >-
      https://github.com/mouse07410/asn1c/security/advisories/GHSA-rcj5-gcvg-x796
  - url: >-
      https://github.com/mouse07410/asn1c/commit/3f7d3bbac8cd195d552945e79586ca5000f33280
    label: >-
      https://github.com/mouse07410/asn1c/commit/3f7d3bbac8cd195d552945e79586ca5000f33280
  - url: >-
      https://github.com/mouse07410/asn1c/commit/71ae41bd1cb146a432a39f72010b48f45ad69463
    label: >-
      https://github.com/mouse07410/asn1c/commit/71ae41bd1cb146a432a39f72010b48f45ad69463
  - url: 'https://github.com/mouse07410/asn1c/releases/tag/v1.2.5'
    label: 'https://github.com/mouse07410/asn1c/releases/tag/v1.2.5'
tags:
  - cve.org
epss: 0.00502
epssPercentile: 0.43192
ingestedAt: '2026-11-05T16:24:31.478Z'
---

## Overview

mouse07410/asn1c is an ASN.1 compiler. Prior to 1.2.5, `OPEN TYPE` decoding can dereference an unallocated member pointer and crash the consuming program. `OPEN_TYPE_aper_get` in `OPEN_TYPE_aper.c`, `OPEN_TYPE_ber_get` in `OPEN_TYPE_ber.c`, `OPEN_TYPE_oer_get` in `OPEN_TYPE_oer.c`, and `OPEN_TYPE_uper_get` in `OPEN_TYPE_uper.c` share the pattern: a conditional null check on `*memb_ptr2` resets presence only when the member exists, but execution then unconditionally computes an inner value from that pointer and a member offset. If the `OPEN TYPE` member has not been allocated, the null-pointer arithmetic and subsequent read cause a segmentation fault. The advisory demonstrates UPER and APER crashes for `E2connectionUpdateAcknowledge`, notes that `E2AP` uses APER, and provides a BER reproducer; OER is also explicitly identified as affected. This issue is fixed in version 1.2.5.

## Affected

- `asn1c < 1.2.5`

## Remediation

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