CVE-2023-28163
MediumCVSS 6.5Exploitation Probability (EPSS)
Elevated risk56th percentile - higher than 56% of all known CVEs
Summary
When downloading files through the Save As dialog on Windows with suggested filenames containing environment variable names, Windows would resolve those in the context of the current user. This bug only affects Firefox on Windows.
Risk Assessment
This could lead to disclosure of user environment information or saving files to unexpected locations, potentially aiding social engineering attacks.
Recommendation
Update Firefox to version 111 or later, Firefox ESR to 102.9 or later, and Thunderbird to 102.9 or later.
Other vulnerabilities in Firefox
See all- CVE-2026-120572High
Incorrect boundary conditions in the Layout: Block and Inline component. This vulnerability was fixed in Firefox 159.0.1.
- CVE-2026-113470Medium
Mozilla blocked compromised intermediate eMudhra certificates via OneCRL on October 17, and the list was distributed to clients via RemoteSettings the same day. This update contains the updated OneCRL block list, ensuring clients will block the compromised certificates even if RemoteSettings is disabled by policy or otherwise unavailable in the user's network environment. The vulnerability was fixed in Firefox 158.0.1, Firefox ESR 153.5.1, Firefox ESR 115.43.1, Thunderbird 158.0.1, and Thunderbird 153.5.1.
- CVE-2026-113401Medium
A denial-of-service vulnerability exists in the PDF Viewer component. The vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
- CVE-2026-109780Critical
Vulnerability in the DOM: Core & HTML component allows mitigation bypass. This issue was fixed in Firefox 158 and Thunderbird 158.
- CVE-2026-109774Critical
Invalid pointer and undefined behavior in the DOM: Notifications component. Fixed in Firefox 158 and Thunderbird 158.
- CVE-2026-109772Critical
Same-origin policy bypass in the DevTools component. Fixed in Firefox 158 and Thunderbird 158.
- CVE-2026-109755Critical
A vulnerability in the DOM: Content Processes component allows sandbox escape. It was fixed in Firefox 158 and Thunderbird 158.
- CVE-2026-109750Critical
A vulnerability in the DOM: Web Authentication component causes a site isolation issue. It was fixed in Firefox 158 and Thunderbird 158.
- CVE-2026-109745Critical
Sandbox escape due to uninitialized memory in the DOM: Web Serial component. It was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
- CVE-2026-109740Critical
Sandbox escape due to incorrect boundary conditions in the Widget: Win32 component. The flaw was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
Original NVD description (English source)
When downloading files through the Save As dialog on Windows with suggested filenames containing environment variable names, Windows would have resolved those in the context of the current user. <br>*This bug only affects Firefox on Windows. Other versions of Firefox are unaffected.*. This vulnerability affects Firefox < 111, Firefox ESR < 102.9, and Thunderbird < 102.9.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS