CVE-2023-4578: Mozilla Firefox
Affects Mozilla FirefoxSource CVE Database V5
Not known to be exploited : upgrade to 117 or 115.2 when convenient.
Data as of 26 Oct 2026, 09:08 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 49% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 117, 115.2
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 26 Oct 2026.
What to do
Upgrade Mozilla Firefox to 117 or 115.2.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mozilla Firefox | Affected
| Fixed in
|
AI-suggested
Mozilla has released official fixes for this vulnerability in Firefox 117 and Thunderbird 115.2. Users and administrators should update to these versions or later to remediate the issue. No additional mitigation steps are required beyond applying the official updates.
Description
CVE-2023-4578 is a moderate impact vulnerability in Mozilla Firefox and Thunderbird's SpiderMonkey JavaScript engine. It involves error reporting methods where an Out of Memory exception could be mishandled as a Syntax Error due to memory allocation attempts when memory is unavailable. This flaw affects Firefox versions prior to 117 and Thunderbird versions prior to 115.2. The issue has been fixed in Firefox 117 and Thunderbird 115.2.