CVE-2023-4578: mozilla firefox
Vulnerability summary
CVE-2023-4578 is a medium (CVSS 6.5) vulnerability in mozilla firefox. EPSS estimates a 0.62% chance of exploitation in the next 30 days, higher than 48.8% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 25 · Related 10Timeline
- 11-09-2023PublishedVulnerability first disclosed.
- 18-12-2025Last modifiedVulnerability information updated.
Description
When calling `JS::CheckRegExpSyntax` a Syntax Error could have been set which would end in calling `convertToRuntimeErrorAndClear`. A path in the function could attempt to allocate memory when none is available which would have caused a newly created Out of Memory exception to be mishandled as a Syntax Error. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thunderbird < 115.2.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
- OSV · ChainguardEcosystem advisory · calculated6.5MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.62%
Chance of exploitation in the next 30 days
Percentile
49%
Versus all other CVEs
30-day change
0.00 pp
From 0.62% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu8 products
- firefox< 117.0+build2-0ubuntu0.20.04.1
- mozjs102All versions (No fix recorded)
- mozjs38All versions (No fix recorded)
- mozjs52All versions (No fix recorded)
- mozjs68All versions (No fix recorded)
Mozilla3 products
- firefox≥ unspecified, < 117 | < 117.0
- firefox_esr≥ unspecified, < 115.2 | < 115.2
- thunderbird≥ unspecified, < 115.2 | < 115.2
Debian2 products
- firefox-esr< 115.2.0esr-1
- thunderbird< 1:115.2.0-1
Chainguard1 product
- firefox-esr< 117.0-r0
4 vendors · 14 products
