# RHSA-2021:2883: thunderbird security update

RHSA-2021:2883, released July 26, 2021, fixes 4 CVEs in thunderbird (version 0:78.12.0-3.el8_4). None of them is reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/fix/linux/rhsa-2021-2883
- Platform: Linux
- Released: Jul 26, 2021
- Priority: High (Closes CVE-2021-30547, high severity)
- CVEs: 4, exploited: 0, on CISA KEV: 0
- Vendor advisory: https://access.redhat.com/errata/RHSA-2021:2883

## Applies to

| Product | Release | Fixed in |
|---|---|---|
| [thunderbird](https://patchblox.com/security/data/product/linux/thunderbird.md) | RHEL 8 | 0:78.12.0-3.el8_4 |

## CVEs this fix closes

| CVE | Priority | Title | CVSS | EPSS | Exploitation |
|---|---|---|---:|---:|---|
| [CVE-2021-30547](https://patchblox.com/security/data/cve/CVE-2021-30547.md) | High | Chromium: CVE-2021-30547 Out of bounds write in ANGLE | 8.8 | 0.0361 |  |
| [CVE-2021-29970](https://patchblox.com/security/data/cve/CVE-2021-29970.md) | High | Firefox ESR and 3 others: A malicious webpage could have triggered a use-after-free, memory corruption, and a potentially exploitable… | 8.8 | 0.0143 |  |
| [CVE-2021-29976](https://patchblox.com/security/data/cve/CVE-2021-29976.md) | High | Firefox ESR and 3 others: Mozilla developers reported memory safety bugs present in code shared between Firefox and Thunderbird. | 8.8 | 0.0122 |  |
| [CVE-2021-29969](https://patchblox.com/security/data/cve/CVE-2021-29969.md) | Routine | Thunderbird and 1 other: If Thunderbird was configured to use STARTTLS for an IMAP connection, and an attacker injected IMAP server… | 5.9 | 0.0120 |  |

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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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo