302823 2025-11-19 14:13:26 -0800 Safari 26: Websocket fails to connect "The network connection was lost" in case of simultaneous http request to the same server 2026-01-22 11:37:59 -0800 1 1 1 Unclassified WebKit New Bugs Safari 26 All iOS 26 RESOLVED MOVED InRadar P2 Major --- 1 dmendez webkit-unassigned ap dmendez joseph.belmonte romankimlicek5 webkit-bug-importer zhenchao_li oldest_to_newest 2160060 0 dmendez 2025-11-19 14:13:26 -0800 Steps to reproduce: 1. Restart Safari 26 2. Go to https://jsfiddle.net/qbh8gLne/13/ 3. Click "open websocket" Results: - The "error" event fires for the websocket - console shows error "The network connection was lost" The problem does not appear to happen if: - The fetch is to a different server - The fetch is awaited before opening the websocket - Safari is not restarted Sample User Agent strings for users who have encountered this problem: Mozilla/5.0+(iPhone;+CPU+iPhone+OS+18_7+like+Mac+OS+X)+AppleWebKit/605.1.15+(KHTML,+like+Gecko)+Version/26.1+Mobile/15E148+Safari/604.1 Mozilla/5.0+(Macintosh;+Intel+Mac+OS+X+10_15_7)+AppleWebKit/605.1.15+(KHTML,+like+Gecko)+Version/26.1+Safari/605.1.15 Mozilla/5.0+(Macintosh;+Intel+Mac+OS+X+10_15_7)+AppleWebKit/605.1.15+(KHTML,+like+Gecko)+Version/26.0.1+Safari/605.1.15 Mozilla/5.0+(Macintosh;+Intel+Mac+OS+X+10_15_7)+AppleWebKit/605.1.15+(KHTML,+like+Gecko)+Version/26.0.1+Safari/605.1.15 Mozilla/5.0+(iPhone;+CPU+iPhone+OS+18_7+like+Mac+OS+X)+AppleWebKit/605.1.15+(KHTML,+like+Gecko)+Version/26.1+Mobile/15E148+Safari/604.1 Mozilla/5.0+(iPhone;+CPU+iPhone+OS+18_7+like+Mac+OS+X)+AppleWebKit/605.1.15+(KHTML,+like+Gecko)+Version/26.1+Mobile/15E148+Safari/604.12 Mozilla/5.0+(iPhone;+CPU+iPhone+OS+18_7+like+Mac+OS+X)+AppleWebKit/605.1.15+(KHTML,+like+Gecko)+Version/26.0.1+Mobile/15E148+Safari/604.1 Could this be related to https://bugs.webkit.org/show_bug.cgi?id=215631? 2160381 1 dmendez 2025-11-20 15:01:48 -0800 Is there any update on this, particularly if there is a server side workaround we could implement? This is starting to affect many of our Safari users. 2160694 2 ap 2025-11-21 13:38:49 -0800 I was about to say that this seemed more like bug 302561, but (1) that one is reported to be an iOS 26.1 regression, and (2) I can reproduce this one without iCloud Private Relay. Such WebSocket issues are generally in an underlying networking library below WebKit, so I'll move this bug to Apple internal system for Apple engineers to investigate. > This is starting to affect many of our Safari users. If you could describe the impact (how many people are affected and how badly), that would help with prioritization. Please feel free to email me if you prefer to not share this information publicly. 2160695 3 webkit-bug-importer 2025-11-21 13:38:55 -0800 <rdar://problem/165232100> 2166743 4 zhenchao_li 2025-12-17 15:11:06 -0800 I can reproduce the websocket error in Safari. However if I try Chrome it is giving me the same error. I wonder if anything has since changed on the server side? I can continue to investigate but would be good to confirm whether this is still an issue that only happens in Safari. 2168621 5 dmendez 2025-12-30 12:38:51 -0800 I just tried a few different browsers and these are my results: Chrome on Windows (Version 143.0.7499.170 (Official Build) (64-bit)) - OK Safari 26.2 on Tahoe desktop - ERROR Chrome 143 on Tahoe desktop - OK Chrome on iphone 17 26.0 - OK Safari on iphone 17 26.0 - ERROR 2174174 6 dmendez 2026-01-22 11:25:43 -0800 (In reply to Alexey Proskuryakov from comment #2) > I was about to say that this seemed more like bug 302561, but (1) that one > is reported to be an iOS 26.1 regression, and (2) I can reproduce this one > without iCloud Private Relay. > > Such WebSocket issues are generally in an underlying networking library > below WebKit, so I'll move this bug to Apple internal system for Apple > engineers to investigate. > > > This is starting to affect many of our Safari users. > > If you could describe the impact (how many people are affected and how > badly), that would help with prioritization. Please feel free to email me if > you prefer to not share this information publicly. This is marked "resolved moved". Was it moved to another bug system? 2174178 7 ap 2026-01-22 11:37:59 -0800 Yes: > Such WebSocket issues are generally in an underlying networking library below WebKit, so I'll move this bug to Apple internal system for Apple engineers to investigate. There are no updates to share here.