Question 1

Is there a bug in hashbrown 0.15.0?

Accepted Answer

Borsh serialization of HashMap is non-canonical The borsh serialization of the HashMap did not follow the borsh specification. It potentially produced non-canonical encodings dependent on insertion order. It also did not perform canonicty checks on decoding.

This can result in consensus splits and cause equivalent objects to be considered distinct.

This was patched in 0.15.1. Fixed in hashbrown 0.15.1.

Question 2

Is there a bug in hashbrown 0.15.0?

Accepted Answer

Borsh serialization of HashMap is non-canonical The borsh serialization of the HashMap did not follow the borsh specification.
It potentially produced non-canonical encodings dependent on insertion order.
It also did not perform canonicty checks on decoding.

This can result in consensus splits and cause equivalent objects to be
considered distinct.

This was patched in 0.15.1. Fixed in hashbrown 0.15.1.

Severity	Affected	Fixed in	Title	Status	Source
high	0.15.0	0.15.1	Borsh serialization of HashMap is non-canonical The borsh serialization of the HashMap did not follow the borsh specification. It potentially produced non-canonical encodings dependent on insertion order. It also did not perform canonicty checks on decoding. This can result in consensus splits and cause equivalent objects to be considered distinct. This was patched in 0.15.1.	fixed	osv:GHSA-wwq9-3cpr-mm53
medium	0.15.0	0.15.1	Borsh serialization of HashMap is non-canonical The borsh serialization of the HashMap did not follow the borsh specification. It potentially produced non-canonical encodings dependent on insertion order. It also did not perform canonicty checks on decoding. This can result in consensus splits and cause equivalent objects to be considered distinct. This was patched in 0.15.1.	fixed	osv:RUSTSEC-2024-0402

hashbrown known bugs