CVE-2023-4577: mozilla firefox
CVSS: 6.5v3.1MediumModified
AliasesUBUNTU-CVE-2023-4577DEBIAN-CVE-2023-4577CGA-c948-95j8-8pcpCGA-wqgw-5hcm-q2c9
Published 11-09-2023Last modified 18-12-2025
Vulnerability summary
CVE-2023-4577 is a medium (CVSS 6.5) vulnerability in mozilla firefox. EPSS estimates a 0.65% chance of exploitation in the next 30 days, higher than 50.3% of scored vulnerabilities.
CVSS score
6.5/10
010
Medium · v3.1 (NVD)EPSS score
0.65%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 25 · Related 10MGASA-2023-0266OPENSUSE-SU-2024:13176-1OPENSUSE-SU-2024:13202-1OPENSUSE-SU-2024:14572-1RHSA-2023:4945RHSA-2023:4946RHSA-2023:4947RHSA-2023:4948RHSA-2023:4949RHSA-2023:4950RHSA-2023:4951RHSA-2023:4952RHSA-2023:4954RHSA-2023:4955RHSA-2023:4956RHSA-2023:4957RHSA-2023:4958RHSA-2023:4959RHSA-2023:5019SUSE-SU-2023:3519-1SUSE-SU-2023:3559-1SUSE-SU-2023:3562-1SUSE-SU-2023:3664-1USN-6320-1USN-6405-1CGA-X7WQ-F787-QGRQ
Timeline
- 11-09-2023PublishedVulnerability first disclosed.
- 18-12-2025Last modifiedVulnerability information updated.
Description
When `UpdateRegExpStatics` attempted to access `initialStringHeap` it could already have been garbage collected prior to entering the function, which could potentially have led to an exploitable crash. This vulnerability affects Firefox < 117, Firefox ESR < 115.2, and Thunderbird < 115.2.
CVSS metrics
4 scores · 4 sources · 1 versionMedium 6.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:HSourcesAll 4 agree
- 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
0.65%
Chance of exploitation in the next 30 days
Percentile
50%
Versus all other CVEs
30-day change
0.00 pp
From 0.65% on 19-09-2026
19-09-202619-10-2026
EPSS score0.65%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected 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
