CVE-2023-6864Network attack vector

Code execution via undisclosed memory corruption

Published Dec 19, 2023 · Updated Aug 2, 2024

Memory corruption in Mozilla Firefox before 121, Firefox ESR before 115.6, and Thunderbird before 115.6 allows remote attackers to run code. Mozilla has not disclosed the individual faulty components or the operations on untrusted content that caused the memory corruption. Exploitation requires user interaction with attacker-controlled content and can execute code in the affected application's context.

CVSS severity8.8
High
EPSS probability1.19%
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 121, Firefox ESR before 115.6, and Thunderbird before 115.6 allows remote attackers to run code. Mozilla has not disclosed the individual faulty components or the operations on untrusted content that caused the memory corruption. Exploitation requires user interaction with attacker-controlled content and can execute code in the affected application's context.

The record

CVE
CVE-2023-6864
Published
Dec 19, 2023
Updated
Aug 2, 2024
Vendor
Mozilla
Product
Firefox
Classifications
CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 19, 2023CVE publishedPublication date reported by the CVE source.
  2. Aug 2, 2024Record 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 <121

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <121
Mozilla · Thunderbirdversion=unspecified <115.6
Mozilla · Firefox ESRversion=unspecified <115.6

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 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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