# DLA-4311-1: thunderbird security update

DLA-4311-1, released September 26, 2025, fixes 1 CVE in thunderbird (version 1:140.3.0esr-1~deb11u1). None of them is reported as exploited. Patch Radar priority: High. The product is no longer supported.

- Web page: https://patchblox.com/security/fix/linux/dla-4311-1
- Platform: Linux
- Released: Sep 26, 2025
- Priority: High (Closes CVE-2025-10527, high severity)
- CVEs: 1, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://security-tracker.debian.org/tracker/CVE-2025-10527

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [thunderbird](https://patchblox.com/security/data/product/linux/thunderbird.md) | Debian 11.6 (bullseye) | 1:140.3.0esr-1~deb11u1 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2025-10527](https://patchblox.com/security/data/cve/CVE-2025-10527.md) | High | Sandbox escape due to use-after-free in the Graphics: Canvas2D component | 7.5 | 0.0029 |  |

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Data as of 2026-11-07T12:40:37Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo