# RLSA-2026:65159: thunderbird security update

RLSA-2026:65159, released September 9, 2026, fixes 21 CVEs in thunderbird (version 0:140.14.0-1.el10_2). None of them is reported as exploited. Patch Radar priority: Urgent.

- Web page: https://patchblox.com/security/fix/linux/rlsa-2026-65159
- Platform: Linux
- Released: Sep 9, 2026
- Priority: Urgent (Closes CVE-2026-74964, rated Critical)
- CVEs: 21, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://errata.rockylinux.org/RLSA-2026:65159

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [thunderbird](https://patchblox.com/security/data/product/linux/thunderbird.md) | rocky 10 | 0:140.14.0-1.el10_2 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2026-74964](https://patchblox.com/security/data/cve/CVE-2026-74964.md) | Urgent | Integer overflow in the Graphics component | 9.8 | 0.0060 |  |
| [CVE-2026-74936](https://patchblox.com/security/data/cve/CVE-2026-74936.md) | Urgent | Use-after-free in the JavaScript: WebAssembly component | 9.8 | 0.0040 |  |
| [CVE-2026-74959](https://patchblox.com/security/data/cve/CVE-2026-74959.md) | Urgent | Mitigation bypass in the Storage: Cache API component | 9.1 | 0.0034 |  |
| [CVE-2026-74945](https://patchblox.com/security/data/cve/CVE-2026-74945.md) | High | Information disclosure in the Graphics: Text component | 7.5 | 0.0071 |  |
| [CVE-2026-74990](https://patchblox.com/security/data/cve/CVE-2026-74990.md) | High | Internally found bugs fixed in Thunderbird ESR 140.14, Thunderbird ESR 153.1 and Thunderbird 154 | 9.8 | 0.0053 |  |
| [CVE-2026-74987](https://patchblox.com/security/data/cve/CVE-2026-74987.md) | High | Internally found bugs fixed in Thunderbird ESR 140.14, Thunderbird ESR 153.1 and Thunderbird 154 | 9.8 | 0.0052 |  |
| [CVE-2026-74971](https://patchblox.com/security/data/cve/CVE-2026-74971.md) | High | Information disclosure in the DOM: UI Events & Focus Handling component | 7.5 | 0.0032 |  |
| [CVE-2026-74976](https://patchblox.com/security/data/cve/CVE-2026-74976.md) | High | JIT miscompilation in the JavaScript Engine: JIT component | 7.5 | 0.0032 |  |
| [CVE-2026-74948](https://patchblox.com/security/data/cve/CVE-2026-74948.md) | High | Information disclosure in the Graphics component | 7.5 | 0.0031 |  |
| [CVE-2026-74935](https://patchblox.com/security/data/cve/CVE-2026-74935.md) | High | Privilege escalation in the DOM: Networking component | 8.8 | 0.0031 |  |
| [CVE-2026-74939](https://patchblox.com/security/data/cve/CVE-2026-74939.md) | High | Privilege escalation in the DOM: Navigation component | 8.8 | 0.0030 |  |
| [CVE-2026-74942](https://patchblox.com/security/data/cve/CVE-2026-74942.md) | High | Privilege escalation in the Remote Settings Client component | 8.8 | 0.0030 |  |
| [CVE-2026-74957](https://patchblox.com/security/data/cve/CVE-2026-74957.md) | High | Mitigation bypass in the Safe Browsing component | 8.1 | 0.0030 |  |
| [CVE-2026-74953](https://patchblox.com/security/data/cve/CVE-2026-74953.md) | High | Privilege escalation in the Networking: Cookies component | 8.8 | 0.0030 |  |
| [CVE-2026-74972](https://patchblox.com/security/data/cve/CVE-2026-74972.md) | High | Information disclosure in the DOM: Push Subscriptions component | 7.5 | 0.0026 |  |
| [CVE-2026-74973](https://patchblox.com/security/data/cve/CVE-2026-74973.md) | High | Race condition, use-after-free in the Graphics component | 7.5 | 0.0018 |  |
| [CVE-2026-74960](https://patchblox.com/security/data/cve/CVE-2026-74960.md) | High | Site isolation issue in the WebExtensions component | 8.1 | 0.0016 |  |
| [CVE-2026-74962](https://patchblox.com/security/data/cve/CVE-2026-74962.md) | High | Site isolation issue in the Networking: Cookies component | 8.1 | 0.0016 |  |
| [CVE-2026-74934](https://patchblox.com/security/data/cve/CVE-2026-74934.md) | High | Site isolation issue in the Graphics: CanvasWebGL component | 7.5 | 0.0016 |  |
| [CVE-2026-74974](https://patchblox.com/security/data/cve/CVE-2026-74974.md) | High | Same-origin policy bypass in the Graphics: ImageLib component | 7.5 | 0.0014 |  |
| [CVE-2026-74963](https://patchblox.com/security/data/cve/CVE-2026-74963.md) | High | Same-origin policy bypass in the Networking: Cookies component | 7.5 | 0.0012 |  |

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Data as of 2026-11-09T01:18:40Z 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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