Is ImageSharp affected by CVE-2023-5129?

[SigmundurMorkore]

Is ImageSharp affected by CVE-2023-5129?

With a specially crafted WebP lossless file, libwebp may write data out of bounds to the heap. The ReadHuffmanCodes() function allocates the HuffmanCode buffer with a size that comes from an array of precomputed sizes: kTableSize. The color_cache_bits value defines which size to use. The kTableSize array only takes into account sizes for 8-bit first-level table lookups but not second-level table lookups. libwebp allows codes that are up to 15-bit (MAX_ALLOWED_CODE_LENGTH). When BuildHuffmanTable() attempts to fill the second-level tables it may write data out-of-bounds. The OOB write to the undersized array happens in ReplicateValue.

• https://www.cve.org/CVERecord?id=CVE-2023-5129

[antonfirsov]

I see no unsafe code in our version of that method or in other related code, so likely there are no buffer overruns and the worst thing that would happen is an IndexOutOfRangeException. It would make it much easier to reproduce/verify this if there was a test image available somewhere.
/cc @brianpopow