sprang, this one too. Looks like it could be related to  bug 671312 . Please dupe it if so.

Yes, this is most likely the same as  bug 671312 . Closing as dupe.

ClusterFuzz has detected this issue as fixed in range 436598:436642.

Detailed report: https://cluster-fuzz.appspot.com/testcase?key=5604629468676096

Fuzzer: libfuzzer_rtcp_receiver_fuzzer
Job Type: libfuzzer_chrome_msan
Platform Id: linux

Crash Type: Use-of-uninitialized-value
Crash Address: 
Crash State:
  webrtc::RTCPReceiver::HandleXrTargetBitrate
  webrtc::RTCPReceiver::HandleXr
  webrtc::RTCPReceiver::ParseCompoundPacket
  
Recommended Security Severity: Medium

Regressed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_msan&range=436251:436277
Fixed: https://cluster-fuzz.appspot.com/revisions?job=libfuzzer_chrome_msan&range=436598:436642

Minimized Testcase (1.20 Kb): https://cluster-fuzz.appspot.com/download/AMIfv95hmx0rkh5gZ7G9ZhO4onazdgJPQ_L8Awc-0SFaiPWs1ExZHZPIPeVTUElnkXGCGABnmDi9H5quWsdHbR9slMpkBjLgGpKPUn_DZlaM2QOJuLxYWaooY-SksbeT69ETzN239RDIQGayNmKvfMY5oBmwTS9tfg?testcase_id=5604629468676096

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.

This bug has been closed for more than 14 weeks. Removing security view restrictions.

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