CVE-2023-32209Public exploitNetwork attack vector

Persistent browser crash via oversized favicon

Published Jun 19, 2023 · Updated May 27, 2025

Denial of service in Mozilla Firefox before 113 allows remote attackers to crash the browser through a crafted favicon. Firefox ImageLib accepts enormous dimensions declared by a tiny JPEG favicon and attempts a correspondingly large image allocation, exhausting memory. Loading the page can crash its sandboxed tab, while favicon history can retrigger browser-wide exhaustion after restart.

CVSS severity7.5
High
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Mozilla Firefox before 113 allows remote attackers to crash the browser through a crafted favicon. Firefox ImageLib accepts enormous dimensions declared by a tiny JPEG favicon and attempts a correspondingly large image allocation, exhausting memory. Loading the page can crash its sandboxed tab, while favicon history can retrigger browser-wide exhaustion after restart.

The record

CVE
CVE-2023-32209
Published
Jun 19, 2023
Updated
May 27, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 19, 2023CVE publishedPublication date reported by the CVE source.
  2. May 27, 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 <113

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <113

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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-787Out-of-bounds Write
T1499.004Application or System Exploitation

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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