CVE-2024-2616Network attack vector

Memory corruption via ICU allocation-failure handling

Published Mar 19, 2024 · Updated Feb 13, 2025

Use-after-free in ICU in Mozilla Firefox ESR and Thunderbird before 115.9 allows attackers to corrupt memory via an out-of-memory condition. ICU can deallocate a shared UnicodeString array after allocation failure without propagating the failed state to every referencing instance, leading later release operations to access freed storage. Reaching the flaw requires an out-of-memory condition in ICU; affected processes can crash, and the stale shared state creates a use-after-free risk.

CVSS severity2.7
Low
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

Use-after-free in ICU in Mozilla Firefox ESR and Thunderbird before 115.9 allows attackers to corrupt memory via an out-of-memory condition. ICU can deallocate a shared UnicodeString array after allocation failure without propagating the failed state to every referencing instance, leading later release operations to access freed storage. Reaching the flaw requires an out-of-memory condition in ICU; affected processes can crash, and the stale shared state creates a use-after-free risk.

The record

CVE
CVE-2024-2616
Published
Mar 19, 2024
Updated
Feb 13, 2025
Vendor
Mozilla
Product
Thunderbird
Classifications
CWE-787, T1499
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 19, 2024CVE 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 <115.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

Mozilla · Thunderbirdversion=unspecified <115.9
Mozilla · Firefox ESRversion=unspecified <115.9

Published CVSS scores

2.7NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L
2.7CISA-ADPCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:L

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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