---
id: CVE-2023-29535
title: >-
  Following a Garbage Collector compaction, weak maps may have been accessed
  before they were correctly traced
summary: >-
  Following a Garbage Collector compaction, weak maps may have been accessed
  before they were correctly traced. This resulted in memory corruption and a
  potentially exploitable crash. This vulnerability affects Firefox < 112, Focus
  for And…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
vendor: mozilla
product: firefox
affected:
  - firefox < 112.0
  - firefox_esr < 102.10
  - firefox_mobile < 112.0
  - focus < 112.0
  - thunderbird < 102.10
patched:
  - firefox 112.0
  - firefox_esr 102.10
  - firefox_mobile 112.0
  - focus 112.0
  - thunderbird 102.10
published: '2023-06-02'
updated: '2026-08-19'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2023-29535'
references:
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1820543'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2023-13/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2023-14/'
    label: security@mozilla.org
  - url: 'https://www.mozilla.org/security/advisories/mfsa2023-15/'
    label: security@mozilla.org
  - url: 'https://bugzilla.mozilla.org/show_bug.cgi?id=1820543'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.mozilla.org/security/advisories/mfsa2023-13/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.mozilla.org/security/advisories/mfsa2023-14/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.mozilla.org/security/advisories/mfsa2023-15/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00747
epssPercentile: 0.5284
ingestedAt: '2026-08-19T15:41:15.442Z'
---

## Overview

Following a Garbage Collector compaction, weak maps may have been accessed before they were correctly traced. This resulted in memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 112, Focus for Android < 112, Firefox ESR < 102.10, Firefox for Android < 112, and Thunderbird < 102.10.

## Affected

- `firefox < 112.0`
- `firefox_esr < 102.10`
- `firefox_mobile < 112.0`
- `focus < 112.0`
- `thunderbird < 102.10`

## Remediation

Upgrade past the affected range:

- `firefox 112.0`
- `firefox_esr 102.10`
- `firefox_mobile 112.0`
- `focus 112.0`
- `thunderbird 102.10`