Predator and CL could not provide any possible suspects.
Using Code Search for the file, "cfx_retain_ptr.h" assigning to concern owner.

Suspecting Commit#
https://pdfium.googlesource.com/pdfium.git/+/3bb57514867a2bd10ba535e0b06de566a58d8085

@tsepez -- Could you please look into the issue, kindly re-assign if this is not related to your changes.
Thank You.

ClusterFuzz has detected this issue as fixed in range 496693:496738.

Detailed report: https://clusterfuzz.com/testcase?key=6699792964255744

Fuzzer: libFuzzer_pdfium_fuzzer
Job Type: libfuzzer_chrome_asan_debug
Platform Id: linux

Crash Type: Null-dereference READ
Crash Address: 0x000000000068
Crash State:
  CFX_RetainPtr<CPDF_Image>::Get
  CFX_RetainPtr<CPDF_Image>::CFX_RetainPtr
  CPDF_ImageObject::GetImage
  
Sanitizer: address (ASAN)

Regressed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_asan_debug&range=494985:495056
Fixed: https://clusterfuzz.com/revisions?job=libfuzzer_chrome_asan_debug&range=496693:496738

Reproducer Testcase: https://clusterfuzz.com/download?testcase_id=6699792964255744

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.