The kimageformats library contains a stack-use-after-scope vulnerability in the StreamReader_CApi::wait_for_file_size function, as reported by OSS-Fuzz. The crash involves reading 8 bytes from a stack variable that has gone out of scope, potentially causing memory corruption. The issue appears during the processing of HEIF files, specifically in the Box_iloc::read_data and HeifFile::append_data_from_iloc functions. Affected versions are explicitly identified as 6.28.0, 6.28.0-rc1, 6.28.1, 6.29.0-rc1, and 6.29.0. No CVSS score or vendor advisory is available, and no patch links have been provided.

This vulnerability could lead to memory corruption due to use-after-scope on the stack, which might cause application crashes or potentially allow an attacker to influence program behavior. However, no known exploits are reported, and the exact impact depends on how the vulnerable code is used in practice.

Patch status is not yet confirmed — check the vendor advisory or OSS-Fuzz reports for current remediation guidance. Until a fix is available, avoid processing untrusted HEIF files with affected versions of kimageformats or use alternative libraries if possible.