# DLA-4510-1: firefox-esr security update

DLA-4510-1, released March 26, 2026, fixes 1 CVE in firefox-esr (version 140.9.0esr-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-4510-1
- Platform: Linux
- Released: Mar 26, 2026
- Priority: High (Closes CVE-2025-59375, high severity)
- CVEs: 1, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://security-tracker.debian.org/tracker/CVE-2025-59375

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [firefox-esr](https://patchblox.com/security/data/product/linux/firefox-esr.md) | Debian 11.6 (bullseye) | 140.9.0esr-1~deb11u1 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2025-59375](https://patchblox.com/security/data/cve/CVE-2025-59375.md) | High | libexpat in Expat before 2.7.2 allows attackers to trigger large dynamic memory allocations via a small document that is submitted for parsing. | 8.1 | 0.0138 |  |

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Data as of 2026-11-07T06:34:28Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo