CVE-2023-5730Network attack vector

Arbitrary code execution via memory corruption

Published Oct 24, 2023 · Updated Feb 13, 2025

Memory corruption in Mozilla Firefox before 119, Firefox ESR before 115.4, and Thunderbird before 115.4.1 allows attackers to run code. Mozilla groups twelve memory-safety defects under this identifier but does not publish the affected code paths or faulty operations. Mozilla states that Thunderbird generally blocks exploitation through email because scripting is disabled, while browser or browser-like contexts remain exposed.

CVSS severity9.8
Critical
EPSS probability1.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Mozilla Firefox before 119, Firefox ESR before 115.4, and Thunderbird before 115.4.1 allows attackers to run code. Mozilla groups twelve memory-safety defects under this identifier but does not publish the affected code paths or faulty operations. Mozilla states that Thunderbird generally blocks exploitation through email because scripting is disabled, while browser or browser-like contexts remain exposed.

The record

CVE
CVE-2023-5730
Published
Oct 24, 2023
Updated
Feb 13, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 24, 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

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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 <119

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <119
Mozilla · Thunderbirdversion=unspecified <115.4.1
Mozilla · Firefox ESRversion=unspecified <115.4

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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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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