CVE-2024-6602Public exploitNetwork attack vector

Memory corruption via mismatched arena deallocation

Published Jul 9, 2024 · Updated Nov 3, 2025

Memory corruption in NSS in Firefox before 128, Firefox ESR before 115.13, and Thunderbird before 128 allows remote attackers to corrupt memory. SECITEM_ArenaDupItem calls PORT_Free after a data allocation fails even when the SECItem came from an arena allocator. The path requires a fallible arena allocation to return null; a debugger demonstrated crashes and access violations, but malformed-certificate triggering was not reproduced.

CVSS severity9.8
Critical
EPSS probability0.98%
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 NSS in Firefox before 128, Firefox ESR before 115.13, and Thunderbird before 128 allows remote attackers to corrupt memory. SECITEM_ArenaDupItem calls PORT_Free after a data allocation fails even when the SECItem came from an arena allocator. The path requires a fallible arena allocation to return null; a debugger demonstrated crashes and access violations, but malformed-certificate triggering was not reproduced.

The record

CVE
CVE-2024-6602
Published
Jul 9, 2024
Updated
Nov 3, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-94
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 9, 2024CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 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=0 <128
  2. Affected versionversion=unspecified <128

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=0 <128; version=unspecified <128
Mozilla · Thunderbirdversion=unspecified <115.13; version=unspecified <128
Mozilla · Firefox ESRversion=0 <115.13; version=unspecified <115.13

Published CVSS scores

9.8CISA-ADPCVSS: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.

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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 exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')

Public exploit references

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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