Reported

April 24, 2025

Issued

August 11, 2026

Package

stainless_ffmpeg (crates.io)

Type

INFO Unsound

References

• https://github.com/nomalab/stainless-ffmpeg/issues/63
• https://github.com/nomalab/stainless-ffmpeg/pull/64
• https://github.com/nomalab/stainless-ffmpeg/commit/a649e8cb4e7c9859279d1dc85051df5e7a4932f7

Patched

• >=0.6.0

Affected Functions

Version

stainless_ffmpeg::format_context::FormatContext::get_codec_id

• <0.6.0

stainless_ffmpeg::format_context::FormatContext::get_stream

• <0.6.0

stainless_ffmpeg::format_context::FormatContext::get_stream_type

• <0.6.0

stainless_ffmpeg::format_context::FormatContext::get_stream_type_name

• <0.6.0

Description

Affected versions of stainless_ffmpeg exposed several safe public methods on FormatContext that accepted a stream_index parameter and used it in unsafe pointer operations without checking whether the index was valid. These methods performed pointer arithmetic and dereferenced the resulting stream pointer. Safe callers could pass a negative or out-of-bounds stream_index, which could cause out-of-bounds pointer access and undefined behavior from safe Rust code.

The issue was fixed in version 0.6.0 by marking the affected stream accessor methods as unsafe and documenting that callers must ensure stream_index is a valid stream index.

Advisory available under CC0-1.0 license.