# Firefox Developer Edition (en-US) 135.0

Firefox Developer Edition (en-US) 135.0, released January 24, 2025, fixes 13 CVEs in Firefox Developer Edition (en-US). None of them is reported as exploited. Patch Radar priority: High. The latest Firefox Developer Edition (en-US) is 156.0, which also fixes every one of these CVEs.

- Web page: https://patchblox.com/security/fix/windows-app/mozilla.firefox.developeredition-135.0
- Platform: Windows apps
- Released: Jan 24, 2025
- Priority: High (Closes CVE-2025-1009, high severity)
- CVEs: 13, exploited: 0, on CISA KEV: 0
- Superseded by: [Firefox Developer Edition (en-US) 156.0](https://patchblox.com/security/data/product/windows-app/firefox-developer-edition-en-us.md), the latest version, which also fixes every CVE listed here

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [Firefox Developer Edition (en-US)](https://patchblox.com/security/data/product/windows-app/firefox-developer-edition-en-us.md) |  | 135.0 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2025-1009](https://patchblox.com/security/data/cve/CVE-2025-1009.md) | High | Use-after-free in XSLT | 9.8 | 0.0121 |  |
| [CVE-2025-1011](https://patchblox.com/security/data/cve/CVE-2025-1011.md) | High | A bug in WebAssembly code generation could result in a crash | 8.8 | 0.0063 |  |
| [CVE-2025-1016](https://patchblox.com/security/data/cve/CVE-2025-1016.md) | High | Memory safety bugs fixed in Firefox 135, Thunderbird 135, Firefox ESR 115.20, Firefox ESR 128.7, Thunderbird 115.20, and Thunderbird 128.7 | 9.8 | 0.0059 |  |
| [CVE-2025-1017](https://patchblox.com/security/data/cve/CVE-2025-1017.md) | High | Memory safety bugs fixed in Firefox 135, Thunderbird 135, Firefox ESR 128.7, and Thunderbird 128.7 | 9.8 | 0.0058 |  |
| [CVE-2025-1937](https://patchblox.com/security/data/cve/CVE-2025-1937.md) | High | Memory safety bugs fixed in Firefox 136, Thunderbird 136, Firefox ESR 115.21, Firefox ESR 128.8, and Thunderbird 128.8 | 8.8 | 0.0056 |  |
| [CVE-2025-1020](https://patchblox.com/security/data/cve/CVE-2025-1020.md) | High | Memory safety bugs fixed in Firefox 135 and Thunderbird 135 | 9.8 | 0.0054 |  |
| [CVE-2025-1010](https://patchblox.com/security/data/cve/CVE-2025-1010.md) | High | Use-after-free in Custom Highlight | 8.8 | 0.0046 |  |
| [CVE-2025-1012](https://patchblox.com/security/data/cve/CVE-2025-1012.md) | High | Use-after-free during concurrent delazification | 8.8 | 0.0045 |  |
| [CVE-2025-1014](https://patchblox.com/security/data/cve/CVE-2025-1014.md) | High | Certificate length was not properly checked | 8.8 | 0.0039 |  |
| [CVE-2025-1938](https://patchblox.com/security/data/cve/CVE-2025-1938.md) | High | Memory safety bugs fixed in Firefox 136, Thunderbird 136, Firefox ESR 128.8, and Thunderbird 128.8 | 8.8 | 0.0034 |  |
| [CVE-2025-1013](https://patchblox.com/security/data/cve/CVE-2025-1013.md) | High | Potential opening of private browsing tabs in normal browsing windows | 8.8 | 0.0033 |  |
| [CVE-2025-1018](https://patchblox.com/security/data/cve/CVE-2025-1018.md) | Routine | Fullscreen notification is not displayed when fullscreen is re-requested | 5.3 | 0.0042 |  |
| [CVE-2025-1019](https://patchblox.com/security/data/cve/CVE-2025-1019.md) | Routine | Fullscreen notification not properly displayed | 4.3 | 0.0036 |  |

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Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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