# RHSA-2025:8756: thunderbird security update

RHSA-2025:8756, released June 10, 2025, fixes 13 CVEs in thunderbird (version 0:128.11.0-1.el8_10). None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2025-8756
- Platform: Linux
- Released: Jun 10, 2025
- Priority: High (Closes CVE-2025-4918, high severity)
- CVEs: 13, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2025:8756

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [thunderbird](https://patchblox.com/security/data/product/linux/thunderbird.md) | RHEL 8 | 0:128.11.0-1.el8_10 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2025-4918](https://patchblox.com/security/data/cve/CVE-2025-4918.md) | High | Out-of-bounds access when resolving Promise objects | 9.8 | 0.0952 |  |
| [CVE-2025-4919](https://patchblox.com/security/data/cve/CVE-2025-4919.md) | High | Out-of-bounds access when optimizing linear sums | 8.8 | 0.0912 |  |
| [CVE-2025-5283](https://patchblox.com/security/data/cve/CVE-2025-5283.md) | High | Chromium: CVE-2025-5283 Use after free in libvpx | 8.8 | 0.0064 |  |
| [CVE-2025-5268](https://patchblox.com/security/data/cve/CVE-2025-5268.md) | High | Memory safety bugs fixed in Firefox 139, Thunderbird 139, Firefox ESR 128.11, and Thunderbird 128.11 | 8.8 | 0.0051 |  |
| [CVE-2025-5269](https://patchblox.com/security/data/cve/CVE-2025-5269.md) | High | Memory safety bug fixed in Firefox ESR 128.11 and Thunderbird 128.11 | 8.8 | 0.0048 |  |
| [CVE-2025-3909](https://patchblox.com/security/data/cve/CVE-2025-3909.md) | High | JavaScript Execution via Spoofed PDF Attachment and file:/// Link | 8.8 | 0.0047 |  |
| [CVE-2025-3875](https://patchblox.com/security/data/cve/CVE-2025-3875.md) | High | Sender Spoofing via Malformed From Header in Thunderbird | 8.8 | 0.0040 |  |
| [CVE-2025-3932](https://patchblox.com/security/data/cve/CVE-2025-3932.md) | High | Tracking Links in Attachments Bypassed Remote Content Blocking | 8.8 | 0.0039 |  |
| [CVE-2025-5266](https://patchblox.com/security/data/cve/CVE-2025-5266.md) | High | Script element events leaked cross-origin resource status | 8.8 | 0.0034 |  |
| [CVE-2025-5264](https://patchblox.com/security/data/cve/CVE-2025-5264.md) | High | Potential local code execution in “Copy as cURL” command | 8.8 | 0.0030 |  |
| [CVE-2025-5267](https://patchblox.com/security/data/cve/CVE-2025-5267.md) | High | Clickjacking vulnerability could have led to leaking saved payment card details | 8.8 | 0.0028 |  |
| [CVE-2025-5263](https://patchblox.com/security/data/cve/CVE-2025-5263.md) | High | Error handling for script execution was incorrectly isolated from web content | 8.8 | 0.0027 |  |
| [CVE-2025-3877](https://patchblox.com/security/data/cve/CVE-2025-3877.md) | High | thunderbird: Rejected reason: This CVE was marked as fixed, but due to other code landing - was not actually fixed | 8.8 | n/a |  |

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Data as of 2026-11-07T18:46:35Z 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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