Vulnerability · Published May 14, 2025 · Assigned by mozilla
CVE-2025-3875Sender Spoofing via Malformed From Header in Thunderbird
High 7.5
In plain English
A high-severity authentication bypass by spoofing in Thunderbird from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Thunderbird parses addresses in a way that can allow sender spoofing in case the server allows an invalid From address to be used. For example, if the From header contains an (invalid) value "Spoofed Name ", Thunderbird treats spoofed@example.com as the actual address. This vulnerability was fixed in Thunderbird 128.10.1 and Thunderbird 138.0.1.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | thunderbird | 128.10.1-1.el10_0.alma.1 | ALSA-2025:8196 |
| AlmaLinux:8 | thunderbird | 128.11.0-1.el8_10.alma.1 | ALSA-2025:8756 |
| Debian:12 | thunderbird | 1:128.10.1esr-1~deb12u1 | DSA-5921-1 |
| Debian:12 | thunderbird | 1:128.10.1esr-1~deb12u1 | DEBIAN-CVE-2025-3875 |
| Debian:13 | thunderbird | 1:128.10.1esr-1 | DEBIAN-CVE-2025-3875 |
| Debian:14 | thunderbird | 1:128.10.1esr-1 | DEBIAN-CVE-2025-3875 |
| Rocky Linux:10 | thunderbird | 0:128.10.1-1.el10_0 | RLSA-2025:8196 |
| Rocky Linux:8 | thunderbird | 0:128.11.0-1.el8_10 | RLSA-2025:8756 |
| Rocky Linux:9 | thunderbird | 0:128.10.1-1.el9_6 | RLSA-2025:8203 |
| Ubuntu:22.04:LTS | thunderbird | 1:128.12.0+build1-0ubuntu0.22.04.1 | UBUNTU-CVE-2025-3875 |
| Ubuntu:22.04:LTS | thunderbird | 1:128.12.0+build1-0ubuntu0.22.04.1 | USN-7663-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Thunderbird | see references |
Weakness: CWE-290 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N