CVE-2023-4056Network attack vector

Arbitrary code execution via undisclosed memory corruption

Published Aug 1, 2023 · Updated Feb 13, 2025

Memory-safety defects in Mozilla Firefox 115 and Firefox ESR 102.13 and 115.0 allow remote attackers to execute arbitrary code. Mozilla reports evidence of memory corruption across five security-restricted bug records but does not disclose the affected components or unsafe operations. No authentication is required; successful exploitation grants code execution with the privileges of the affected browser process.

CVSS severity9.8
Critical
EPSS probability0.95%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory-safety defects in Mozilla Firefox 115 and Firefox ESR 102.13 and 115.0 allow remote attackers to execute arbitrary code. Mozilla reports evidence of memory corruption across five security-restricted bug records but does not disclose the affected components or unsafe operations. No authentication is required; successful exploitation grants code execution with the privileges of the affected browser process.

The record

CVE
CVE-2023-4056
Published
Aug 1, 2023
Updated
Feb 13, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 1, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 13, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=0 <116
  2. Affected versionversion=unspecified <116

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=0 <116; version=unspecified <116
Mozilla · Firefox ESRversion=0 <102.14; version=0 <115.1; version=unspecified <102.14; version=unspecified <115.1

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/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-787Out-of-bounds Write
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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