# RHSA-2026:27717: firefox security update RHSA-2026:27717, released June 24, 2026, fixes 29 CVEs in firefox (version 0:140.12.0-1.el8_10). None of them is reported as exploited. Patch Radar priority: Urgent. - Web page: https://patchblox.com/security/fix/linux/rhsa-2026-27717 - Platform: Linux - Released: Jun 24, 2026 - Priority: Urgent (Closes CVE-2026-12297, rated Critical) - CVEs: 29, exploited: 0, on CISA KEV: 0 - Vendor advisory: https://access.redhat.com/errata/RHSA-2026:27717 ## Applies to | Product | Release | Fixed in | |---|---|---| | [firefox](https://patchblox.com/security/data/product/linux/firefox.md) | RHEL 8 | 0:140.12.0-1.el8_10 | ## CVEs this fix closes | CVE | Priority | Title | CVSS | EPSS | Exploitation | |---|---|---|---:|---:|---| | [CVE-2026-12295](https://patchblox.com/security/data/cve/CVE-2026-12295.md) | Urgent | Sandbox escape in the DOM: Navigation component | 9.6 | 0.0039 | | | [CVE-2026-12296](https://patchblox.com/security/data/cve/CVE-2026-12296.md) | Urgent | Sandbox escape in the Security: Process Sandboxing component | 9.6 | 0.0039 | | | [CVE-2026-12297](https://patchblox.com/security/data/cve/CVE-2026-12297.md) | Urgent | Sandbox escape due to incorrect boundary conditions in the Networking component | 9.6 | 0.0039 | | | [CVE-2026-12294](https://patchblox.com/security/data/cve/CVE-2026-12294.md) | Urgent | Sandbox escape in the DOM: Workers component | 9.6 | 0.0036 | | | [CVE-2026-12315](https://patchblox.com/security/data/cve/CVE-2026-12315.md) | Urgent | Mitigation bypass in the DOM: Security component | 9.1 | 0.0025 | | | [CVE-2026-12304](https://patchblox.com/security/data/cve/CVE-2026-12304.md) | Urgent | Same-origin policy bypass in the Networking: Cookies component | 9.1 | 0.0019 | | | [CVE-2026-12292](https://patchblox.com/security/data/cve/CVE-2026-12292.md) | High | Incorrect boundary conditions in the Web Audio component | 8.1 | 0.0049 | | | [CVE-2026-12328](https://patchblox.com/security/data/cve/CVE-2026-12328.md) | High | Memory safety bugs fixed in Firefox ESR 115.37, Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152 | 8.1 | 0.0048 | | | [CVE-2026-12327](https://patchblox.com/security/data/cve/CVE-2026-12327.md) | High | Memory safety bugs fixed in Firefox ESR 140.12, Thunderbird ESR 140.12, Firefox 152 and Thunderbird 152 | 8.1 | 0.0041 | | | [CVE-2026-12290](https://patchblox.com/security/data/cve/CVE-2026-12290.md) | High | Memory safety bug fixed in Thunderbird 152 | 8.1 | 0.0040 | | | [CVE-2026-12289](https://patchblox.com/security/data/cve/CVE-2026-12289.md) | High | Privilege escalation in the Graphics: WebRender component | 8.8 | 0.0040 | | | [CVE-2026-12291](https://patchblox.com/security/data/cve/CVE-2026-12291.md) | High | Use-after-free in the Networking: HTTP component | 8.8 | 0.0038 | | | [CVE-2026-12305](https://patchblox.com/security/data/cve/CVE-2026-12305.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0037 | | | [CVE-2026-12329](https://patchblox.com/security/data/cve/CVE-2026-12329.md) | High | Memory safety bug fixed in Thunderbird ESR 140.12 | 7.5 | 0.0031 | | | [CVE-2026-12298](https://patchblox.com/security/data/cve/CVE-2026-12298.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0031 | | | [CVE-2026-12299](https://patchblox.com/security/data/cve/CVE-2026-12299.md) | High | JIT miscompilation in the DOM: Core & HTML component | 7.5 | 0.0031 | | | [CVE-2026-12306](https://patchblox.com/security/data/cve/CVE-2026-12306.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0026 | | | [CVE-2026-12307](https://patchblox.com/security/data/cve/CVE-2026-12307.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0026 | | | [CVE-2026-12308](https://patchblox.com/security/data/cve/CVE-2026-12308.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0026 | | | [CVE-2026-12310](https://patchblox.com/security/data/cve/CVE-2026-12310.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0025 | | | [CVE-2026-12312](https://patchblox.com/security/data/cve/CVE-2026-12312.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0025 | | | [CVE-2026-12314](https://patchblox.com/security/data/cve/CVE-2026-12314.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0025 | | | [CVE-2026-12302](https://patchblox.com/security/data/cve/CVE-2026-12302.md) | High | Mitigation bypass in the DOM: Security component | 7.5 | 0.0025 | | | [CVE-2026-12309](https://patchblox.com/security/data/cve/CVE-2026-12309.md) | High | Memory safety bug fixed in Thunderbird 152 | 7.5 | 0.0024 | | | [CVE-2026-12325](https://patchblox.com/security/data/cve/CVE-2026-12325.md) | High | Denial-of-service in the Graphics: ImageLib component | 7.5 | 0.0023 | | | [CVE-2026-12324](https://patchblox.com/security/data/cve/CVE-2026-12324.md) | High | Incorrect boundary conditions in the Graphics: CanvasWebGL component | 7.5 | 0.0021 | | | [CVE-2026-12311](https://patchblox.com/security/data/cve/CVE-2026-12311.md) | High | Information disclosure, sandbox escape in the Security: Process Sandboxing component | 7.5 | 0.0019 | | | [CVE-2026-12313](https://patchblox.com/security/data/cve/CVE-2026-12313.md) | High | Information disclosure, sandbox escape in the Security: Process Sandboxing component | 7.5 | 0.0018 | | | [CVE-2026-12330](https://patchblox.com/security/data/cve/CVE-2026-12330.md) | High | Incorrect boundary conditions in the Internationalization component | 7.5 | 0.0016 | | --- Data as of 2026-11-07T18:46:35Z UTC. 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