Predator and CL did not provide any possible suspects.
Using Code Search for the file, "TextIterator.cpp" assigning to concern owner from GIT Blame.

Suspecting Commit#
https://chromium.googlesource.com/chromium/src/+/c8070f461957f5f2aaaf41147538ebe811b4abce

@xiaochengh -- Could you please look into the issue, please re-assign if it has nothing to do with your changes.
Thank You.

CompositeEditCommand::MoveParagraphs (once again) moves |destination| out of document.

Lower to P3 due to low usage of InsertOrderedList command and uncommon HTML.

 Issue 723283  has been merged into this issue.

ClusterFuzz has detected this issue as fixed in range 495542:495750.

Detailed report: https://clusterfuzz.com/testcase?key=4650671835185152

Fuzzer: bj_broddelwerk
Job Type: windows_asan_chrome_no_sandbox
Platform Id: windows

Crash Type: Null-dereference READ
Crash Address: 0x00000000
Crash State:
  blink::TextIteratorAlgorithm<class blink::EditingAlgorithm<class blink::NodeTrav
  blink::TextIteratorAlgorithm<class blink::EditingAlgorithm<class blink::NodeTrav
  blink::CompositeEditCommand::MoveParagraphs
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=windows_asan_chrome_no_sandbox&range=443500:443512
Fixed: https://clusterfuzz.com/revisions?job=windows_asan_chrome_no_sandbox&range=495542:495750

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=4650671835185152

See https://github.com/google/clusterfuzz-tools for more information.

If you suspect that the result above is incorrect, try re-doing that job on the test case report page.

ClusterFuzz testcase 4650671835185152 is verified as fixed, so closing issue as verified.

If this is incorrect, please add ClusterFuzz-Wrong label and re-open the issue.