CVE-2026-5731: firefox 115.34.0, 140.9.0, 149.0.1; +20 more affected products

CVE-2026-5731. CVSS 3.1 base score 9.8 (CRITICAL, Source advisory). EPSS 0.0061 (percentile 0.4853), scored 22-Oct-2026.

Affected technology

firefox · 115.34.0
mozilla

firefox · 140.9.0
mozilla

firefox · 149.0.1
mozilla

thunderbird · 140.9.0
mozilla

thunderbird · 149.0.1
mozilla

Red Hat Enterprise Linux 10 · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 10.0 Extended Update Support · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 7 Extended Lifecycle Support · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8 · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8.2 Advanced Update Support · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8.6 Telecommunications Update Service · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8.8 Telecommunications Update Service · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 9 · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 9.0 Update Services for SAP Solutions · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 9.4 Extended Update Support · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 9.6 Extended Update Support · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 6 · Exact affected versions not specified by the source
Red Hat

Red Hat Enterprise Linux 7 · Exact affected versions not specified by the source
Red Hat

Component: Not specified by the source

Attack conditions (Source advisory, CVSS 3.1): Network (remote) · No privileges required · No user interaction required

Attack conditions (Source advisory, CVSS 3.1): Network (remote) · No privileges required · User interaction required

What an attacker can do

Source advisory’s CVSS 3.1 assessment (base score 9.8/10) rates confidentiality, integrity and availability impact as high. Source advisory’s CVSS 3.1 assessment (base score 8.8/10) rates confidentiality, integrity and availability impact as high. The description does not specify what an attacker can achieve beyond these rated impacts.

Published 24-Oct-2026 15:08 UTC

CWE: CWE-119, CWE-787
CCR priority: 39.4 /100 (P4)
CVSS 3.1: 9.8 /10 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H · Source advisory
EPSS: 0.0061 · percentile 0.48603 · 2026-10-24
KEV: no

Provenance

FIRST EPSS daily exploit-probability · Source record · observed 2026-10-24 15:09:16.138216+00:00 UTC
NVD CVE API 2.0 · Source record · observed 2026-10-24 15:07:27.951960+00:00 UTC

Stable permalink: https://cybercodered.org/item/cve-cve-2026-5731.html