CVE-2026-118011
Low risk· EPSS 4%Exploitation Probability (EPSS)
Low risk4th percentile - higher than 4% of all known CVEs
Summary
Frame poisoning vulnerability in the CSS Parsing and Computation component of Firefox and Thunderbird. It may lead to undefined behavior or potential code execution. The vulnerability was fixed in Firefox 159 and Thunderbird 159.
Risk Assessment
Users of vulnerable versions may be exposed to malicious code execution or application crashes when processing crafted CSS. The risk affects workstations with the vulnerable version installed.
Recommendation
Update Firefox and Thunderbird to version 159 or later. Until updated, restrict opening untrusted content.
Other vulnerabilities in Firefox and Thunderbird
See all- CVE-2026-113400Medium
An uninitialized memory vulnerability in the Audio/Video: cubeb component of Firefox and Thunderbird. The issue was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
- CVE-2026-113399Critical
Incorrect boundary conditions in the SVG component. This vulnerability was fixed in Firefox 158.0.1 and Thunderbird 158.0.1.
- CVE-2023-29542Critical
A newline in a filename could be used to bypass file extension security mechanisms that replace malicious extensions such as .lnk with .download, potentially leading to accidental execution of malicious code. This affects Firefox and Thunderbird on Windows: Firefox < 112, Firefox ESR < 102.10, and Thunderbird < 102.10.
- CVE-2026-118013Low risk· EPSS 4%
Use-after-free vulnerability in the Layout: Images, Video, and HTML Frames component of Firefox and Thunderbird. It may lead to undefined behavior or potential code execution. The vulnerability was fixed in Firefox 159 and Thunderbird 159.
- CVE-2026-118012Low risk· EPSS 4%
Use-after-free vulnerability in the DOM: Animation component of Firefox and Thunderbird. It may lead to undefined behavior or potential code execution. The vulnerability was fixed in Firefox 159 and Thunderbird 159.
- CVE-2026-118010Low risk· EPSS 4%
Use-after-free vulnerability in the Disability Access APIs component of Firefox and Thunderbird. It may lead to undefined behavior or potential code execution. The vulnerability was fixed in Firefox 159 and Thunderbird 159.
- CVE-2026-118009Low risk· EPSS 4%
Integer overflow and use-after-free vulnerability in the Graphics: Text component of Firefox and Thunderbird. It may lead to undefined behavior or potential code execution. The vulnerability was fixed in Firefox 159 and Thunderbird 159.
- CVE-2026-118007Low risk· EPSS 4%
Use-after-free vulnerability in the JavaScript: GC component of Firefox and Thunderbird. It may lead to undefined behavior or potential code execution. The vulnerability was fixed in Firefox 159 and Thunderbird 159.
- CVE-2026-118006Low risk· EPSS 4%
Privilege escalation vulnerability due to use-after-free in the WebRTC: Signaling component of Firefox and Thunderbird. It may lead to privilege escalation within the application context. The vulnerability was fixed in Firefox 159 and Thunderbird 159.
- CVE-2026-118005Low risk· EPSS 4%
Use-after-free vulnerability in the WebRTC: Signaling component of Firefox and Thunderbird. It may lead to undefined behavior or potential code execution. The vulnerability was fixed in Firefox 159 and Thunderbird 159.
Original NVD description (English source)
Frame poisoning in the CSS Parsing and Computation component. This vulnerability was fixed in Firefox 159 and Thunderbird 159.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS