Bug 305304

Summary:

Large number of unclosed `{` in CSS crashes WebKit on iOS

Product:

WebKit

Reporter:

neil

Component:

New Bugs

Assignee:

Nobody <webkit-unassigned>

Status:

RESOLVED DUPLICATE

Severity:

Normal

CC:

koivisto

Priority:

Version:

Safari 26

Hardware:

Unspecified

OS:

iOS 26

Attachments:

Description	Flags
Minimal test case to reproduce crash	none

neil

Reported 2026-01-11 19:07:50 PST

Created attachment 477973 [details] Minimal test case to reproduce crash Steps to reproduce: 1. Open attached minimal test case in Safari on iOS 26.2 Expected behaviour: Page renders Actual behavaiour: WebKit crashes: "A problem repeatedly occurred on {URL}" The page is just a style tag with a load of style declarations that are missing their closing bracket. Obviously this is invalid and the author shouldn't have done it, but it also shouldn't cause a crash! This is reduced from the HTML in a real email a customer of ours (Fastmail) received, and would crash our webmail every time they opened it. Note, I have put in the minimum number of declarations to cause a crash. If I remove any more, the crash no longer occurs.

Attachments
Minimal test case to reproduce crash (2.42 KB, text/html) 2026-01-11 19:07 PST, neil	no flags	Details
View All Add attachment proposed patch, testcase, etc.

Alexey Proskuryakov

Comment 1 2026-01-12 12:54:12 PST

Thank you for the report! I could reproduce this, and from the stack trace, this looks the same as bug 303535. The fix is not in any shipping or beta build yet. *** This bug has been marked as a duplicate of bug 303535 ***

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