Phenomenon
In Internet Explorer 11, when a parent element has contenteditable="true" and a child element has contenteditable="false", double-clicking the non-editable child element can make it editable, bypassing the intended read-only restriction. This issue was addressed in a security update.
Reproduction example
- Create a contenteditable div with
contenteditable="true". - Add a child element with
contenteditable="false". - In Internet Explorer 11, double-click on the non-editable child element.
- Try to edit the content of the child element.
- Observe that editing is possible despite
contenteditable="false".
Observed behavior
- Double-click enables editing: Double-clicking makes non-editable element editable.
- Security issue: Read-only restriction is bypassed.
- IE11-specific: This issue is specific to Internet Explorer 11.
- Security update: Microsoft addressed this in a security update.
- Single-click: Single-click correctly prevents editing.
Expected behavior
contenteditable="false"should always prevent editing.- Double-click should not enable editing in non-editable elements.
- Read-only restriction should be enforced regardless of click type.
- Security should not be compromised by user interaction.
Analysis
This was a security vulnerability in Internet Explorer 11โs contenteditable implementation. The browserโs event handling allowed double-click to override the contenteditable="false" attribute, potentially exposing read-only content to modification.
Workarounds
- Apply Internet Explorer 11 security updates that fix this issue.
- Use alternative methods to create read-only regions (CSS, event prevention).
- Test in updated IE11 to verify the fix is applied.
- Consider using modern browsers that donโt have this vulnerability.
- Implement server-side validation to prevent unauthorized content modification.