---
id: CVE-2025-12829
title: >-
  An uninitialized stack read issue exists in Amazon Ion-C versions <v1.1.4 that
  may allow a threat actor to craft data and serialize it to Ion text in such a
  way that sensitive data in memory could be exposed through UTF-8 escape
  sequence…
summary: >-
  An uninitialized stack read issue exists in Amazon Ion-C versions <v1.1.4 that
  may allow a threat actor to craft data and serialize it to Ion text in such a
  way that sensitive data in memory could be exposed through UTF-8 escape
  sequence…
severity: medium
cvss: 6.2
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-125
published: '2025-11-07'
updated: '2026-10-07'
sourceUpdated: '2026-10-07T21:10:00.200'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-12829'
references:
  - url: 'https://aws.amazon.com/security/security-bulletins/AWS-2025-027/'
    label: ff89ba41-3aa1-4d27-914a-91399e9639e5
  - url: 'https://github.com/amazon-ion/ion-c/releases/tag/v1.1.4'
    label: ff89ba41-3aa1-4d27-914a-91399e9639e5
  - url: >-
      https://github.com/amazon-ion/ion-c/security/advisories/GHSA-7mgf-6x73-5h7r
    label: ff89ba41-3aa1-4d27-914a-91399e9639e5
tags:
  - nvd
epss: 0.00152
epssPercentile: 0.03771
ingestedAt: '2026-10-07T21:54:14.979Z'
---

## Overview

An uninitialized stack read issue exists in Amazon Ion-C versions <v1.1.4 that may allow a threat actor to craft data and serialize it to Ion text in such a way that sensitive data in memory could be exposed through UTF-8 escape sequences. To mitigate this issue, users should upgrade to version v1.1.4.

## Remediation

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