CVE-2023-29536Network attack vector

Memory corruption via JavaScript-triggered invalid free

Published Jun 2, 2023 · Updated Jan 9, 2025

Invalid free in Mozilla Firefox-family browsers before 112 and Thunderbird before 102.10 allows remote attackers to corrupt memory. The memory manager incorrectly frees a pointer that addresses attacker-controlled memory while processing JavaScript. User interaction is required; successful triggering causes an assertion, memory corruption, or an application crash.

CVSS severity8.8
High
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Invalid free in Mozilla Firefox-family browsers before 112 and Thunderbird before 102.10 allows remote attackers to corrupt memory. The memory manager incorrectly frees a pointer that addresses attacker-controlled memory while processing JavaScript. User interaction is required; successful triggering causes an assertion, memory corruption, or an application crash.

The record

CVE
CVE-2023-29536
Published
Jun 2, 2023
Updated
Jan 9, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-416, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 2, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 9, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=unspecified <112

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <112
Mozilla · Thunderbirdversion=unspecified <102.10
Mozilla · Firefox for Androidversion=unspecified <112
Mozilla · Firefox Focus for Androidversion=unspecified <112
Mozilla · Firefox ESRversion=unspecified <102.10

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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