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 am the author of a fuzzer (a tool that uncovered a bug), I'm not affiliated with 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=5225557106360320

Fuzzer: libfuzzer_expat_xml_parse_fuzzer
Job Type: libfuzzer_chrome_ubsan
Platform Id: linux

Crash Type: Undefined-shift
Crash Address: 
Crash State:
  utf8_isNmstrt2
  normal_scanPi
  doProlog
  
Sanitizer: undefined (UBSAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=397275:397295
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_ubsan&range=459024:459032

Reproducer Testcase: https://clusterfuzz.com/download/AMIfv95s9z7JYzHrnD9KGVWYseibaHiKY9Hn5bFaX5NZDqJB5EE7jNwOPXs_-IRgQIetR1qTza4VYPbGOkW6k7avGcEd5XCtRqhQobB_gcugFZQJHfZOTZsTUebLKYR3H0KqUTXa0QR9RvofAW-KC-6VXT9MiLp4cQpr6tUOZLt8Rqk6Oph7i8HTm20LDxH1V1jJHUrPUtZnWzMoBZThbw5lZ-NC6iD3cp_qTf4nfmV23WzGVui1i4Zg4CBH_eqtxJ-JAIEAAKJNP1s64Gu1egkAUcBSKBkZ_zSZDgQ0LjhjenLyIoyThMiR811FscZ6EdxYlqraII36qez8WGNICdvmGdxBiIK4IJfB3oL2ZChYeqV-q1Pauc4?testcase_id=5225557106360320


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 5225557106360320 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.