aizatsky@could you please look into this.please feel free to re-assigned back if needed. thanks in advance !
might be a suspected Changelist: https://chromium.googlesource.com/chromium/src/+/7755511101817d4baed54f361622e3084147079f

I'm sorry, I am the author of a fuzzer (a tool that found a bug), not the expat.

sure , thank you !

Removing EditIssue view restrictions from ClusterFuzz filed bugs. If you believe that this issue should still be restricted, please reapply the label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

ClusterFuzz has detected this issue as fixed in range 459024:459032.

Detailed report: https://clusterfuzz.com/testcase?key=6078975765118976

Fuzzer: libfuzzer_expat_xml_parse_fuzzer
Job Type: libfuzzer_chrome_ubsan
Platform Id: linux

Crash Type: Undefined-shift
Crash Address: 
Crash State:
  big2_scanLt
  doContent
  contentProcessor
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=423338:423416
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=459024:459032

Reproducer Testcase: https://clusterfuzz.com/download/AMIfv94SIOnS8xtjnaewZ8uFI6f8fR15f7HPF4iK9n258Usov1OJcTyl8WdDUlADf73LMmwGfbsaHQOoFXcKNJe1chIJ9thXIwhSvjnhV4s4iHnCeTnstADltmmMT5zy4SEmgS2Z4KFhMKqhxAoNNjTjdzpDEUqtS85a7_yeNzzLDPo1m-n_Ut9DhOKLS8c7O7OCka4PX1M5k0tkKKIIk299p76DrCz2UIAQ1qLVFj8F6r7JTDwoaC4B9wBU6jIcK8QIfXOCR7hlgVic5os6W0Ib1jov9CzI89c-R44NKw47s5CaCx-yHXumEKyh8fOr351mYRI2zNToPr9cFd0lwwSjCoKfauWAySurFRUdMZ1SG3KdfoqYfFo?testcase_id=6078975765118976


See https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/reproducing.md 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 6078975765118976 is verified as fixed, so closing issue.

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

qingchengl fixed this with the expat roll in r459025.