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No exploitation reportedFix available

CVE-2023-5730

No exploitation reported by the sources we read.

  • Published2023-10-25
  • WeaknessCWE-787

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

Memory safety bugs present in Firefox 118, Firefox ESR 115.3, and Thunderbird 115.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.

Timeline

dates in UTC
  1. 2023-10-2518:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2023-5730?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2023-5730?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Debian debian linux
BranchAffectedFixed in
10.0= 10.0no fix published
11.0= 11.0no fix published
Mozilla firefox
BranchAffectedFixed in
119.0< 119.0119.0
Mozilla firefox esr
BranchAffectedFixed in
115.4< 115.4115.4

1 more product in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • firefoxAlmaLinux:9all versions · fixed in 115.4.0-1.el9_2.alma.1and 1 other package
  • firefoxAlmaLinux:8all versions · fixed in 115.4.0-1.el8_8.alma.1
  • thunderbirdAlmaLinux:9all versions · fixed in 115.4.1-1.el9_2.alma
  • thunderbirdAlmaLinux:8all versions · fixed in 115.4.1-1.el8_8.alma.1

Full record on NVD

Fix

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • CISA-ADPSSVC decisionnone2024-09-11
  • OpenCVESSVC decisionnone—
  • NVDCVSS 3.19.8read 2026-10-23
  • NVDweakness (CWE)CWE-787read 2026-10-23
  • FIRST EPSSEPSS score1.6 %2026-10-22
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2023-10-25
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2023-5730?

Memory safety bugs present in Firefox 118, Firefox ESR 115.3, and Thunderbird 115.3. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 119, Firefox ESR < 115.4, and Thunderbird < 115.4.1.

Is CVE-2023-5730 actively exploited?

Active exploitation of CVE-2023-5730 has not been confirmed. Its EPSS score was 1.6% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2023-5730?

CVE-2023-5730 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

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