CVE-2023-29539: Mozilla Firefox

High severity, CVSS 8.8. EPSS: 0.7% chance of exploitation in the next 30 days.

When handling the filename directive in the Content-Disposition header, the filename would be truncated if the filename contained a NULL character. This could have led to reflected file download attacks potentially tricking users to install malware. This vulnerability affects Firefox < 112, Focus for Android < 112, Firefox ESR < 102.10, Firefox for Android < 112, and Thunderbird < 102.10.

Affected products

• Mozilla Firefox: before 112.0 (fixed in 112.0)
• Mozilla Firefox ESR: before 102.10 (fixed in 102.10)
• Mozilla Firefox Mobile: before 112.0 (fixed in 112.0)
• Mozilla Focus: before 112.0 (fixed in 112.0)
• Mozilla Thunderbird: before 102.10 (fixed in 102.10)

Published 2023-06-02. Last modified 2026-08-19.