CVE-2026-0891
High · 8.1CVSS
8.1
EPSS
0.5%
Published
Jan 13, 2026
CISA due date
—
The record
Memory safety bugs present in Firefox ESR 140.6, Thunderbird ESR 140.6, Firefox 146 and Thunderbird 146. 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 was fixed in Firefox 147, Firefox ESR 140.7, Thunderbird 147, and Thunderbird 140.7.
Affected packages
| Ecosystem | Package | Introduced | Fixed |
|---|---|---|---|
| AlmaLinux:9 | firefox | 0 | 140.7.0-1.el9_7.alma.1 |
| AlmaLinux:9 | firefox-x11 | 0 | 140.7.0-1.el9_7.alma.1 |
| AlmaLinux:9 | thunderbird | 0 | 140.7.0-1.el9_7.alma.1 |
| Mageia:9 | firefox | 0 | 140.7.0-1.mga9 |
| Mageia:9 | firefox-l10n | 0 | 140.7.0-1.mga9 |
| Mageia:9 | nss | 0 | 3.120.0-1.mga9 |
| Mageia:9 | thunderbird | 0 | 140.7.0-1.mga9 |
| Mageia:9 | thunderbird-l10n | 0 | 140.7.0-1.mga9 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-ESPOS | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP4-LTSS | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-ESPOS | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise High Performance Computing 15 SP5-LTSS | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise Module for Desktop Applications 15 SP7 | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise Module for Package Hub 15 SP7 | MozillaThunderbird | 0 | 140.7.0-150200.8.251.1 |
| SUSE:Linux Enterprise Server 15 SP4-LTSS | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise Server 15 SP5-LTSS | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise Server 15 SP6-LTSS | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP4 | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP5 | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise Server for SAP Applications 15 SP6 | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| SUSE:Linux Enterprise Workstation Extension 15 SP7 | MozillaThunderbird | 0 | 140.7.0-150200.8.251.1 |
| openSUSE:Leap 15.6 | MozillaFirefox | 0 | 140.7.0-150200.152.216.1 |
| openSUSE:Leap 15.6 | MozillaThunderbird | 0 | 140.7.0-150200.8.251.1 |
| openSUSE:Leap 16.0 | MozillaFirefox | 0 | 140.7.0-160000.1.1 |
| openSUSE:Leap 16.0 | MozillaThunderbird | 0 | 140.8.1-bp160.1.1 |
| openSUSE:Tumbleweed | MozillaFirefox | 0 | 147.0-1.1 |
| openSUSE:Tumbleweed | MozillaThunderbird | 0 | 140.7.0-1.1 |
| openSUSE:Tumbleweed | firefox-esr | 0 | 140.7.0-1.1 |
Related vulnerabilities
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- CVE-2026-0877 Mitigation bypass in the DOM: Security component. Also affects firefox
- CVE-2026-0883 Information disclosure in the Networking component. Also affects firefox
- CVE-2026-0878 Sandbox escape due to incorrect boundary conditions in the Graphics: CanvasWebGL… Also affects firefox
- CVE-2026-0884 Use-after-free in the JavaScript Engine component. Also affects firefox