CVE-2023-4576VulnerabilityPublished 11 Sep 2023Updated 18 Dec 2025

CVE-2023-4576: Mozilla Firefox · Vulnerability

Affects Mozilla FirefoxSource CVE Database V5

Not known to be exploited · fixed in 117 : patch Mozilla Firefox soon.

Data as of 25 Oct 2026, 21:28 UTC

Severity

High

Rated High by the CNA (mozilla) · No CVSS score from NVD or the CNA

EPSS: 0.8% chance of exploitation in 30 days – higher than 57% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 117, 115.2, 102.15

Exploitation evidence

Disclosed: evidence found.
CVE published 11 Sep 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Mozilla Firefox to 117, 115.2 or 102.15.

Affected software

Product	Affected	Fixed in
Mozilla Firefox	Affected <117 <102.15 <115.2	Fixed in 117 102.15 115.2

AI-suggested

Mozilla has released official patches that fix this vulnerability in Firefox 117, Firefox ESR 102.15, and Firefox ESR 115.2. Users and administrators should update affected Firefox installations to these versions or later to remediate the issue. No additional mitigation steps are required beyond applying these updates.

Description

CVE-2023-4576 is a high-impact vulnerability affecting Mozilla Firefox on Windows platforms prior to version 117 and Firefox ESR versions prior to 102.15 and 115.2. It involves an integer overflow in the RecordedSourceSurfaceCreation component that leads to a heap buffer overflow. This flaw could potentially leak sensitive data and enable sandbox escape. Other operating systems are not affected by this vulnerability. Mozilla has released official fixes in Firefox 117, Firefox ESR 102.15, and Firefox ESR 115.2.

Impact

Successful exploitation of this vulnerability could lead to leakage of sensitive data from the browser's memory and potentially allow an attacker to escape the sandbox protections, increasing the risk of further compromise on the affected Windows system. The vulnerability is limited to Firefox on Windows and does not affect other platforms.

Summary

This vulnerability, tracked as CVE-2023-4576, occurs on Windows versions of Mozilla Firefox due to an integer overflow in the RecordedSourceSurfaceCreation function. The overflow results in a heap buffer overflow condition that may leak sensitive information and could allow an attacker to escape the browser's sandbox environment. The issue is specific to Firefox on Windows and does not impact other operating systems. Mozilla addressed this vulnerability in Firefox 117 and corresponding ESR releases 102.15 and 115.2. The vendor advisory classifies the impact as high and confirms the availability of patches.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 25 Oct 2026, 21:28 UTC

Technical details

References

Community reviews

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