GHSA-qq4c-hm99-979m IdMap from_iter may lead to uninitialized memory being freed on drop
A flaw in the IdMap library's from_iter constructor can cause uninitialized memory to be freed, leading to crashes or potential code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-qq4c-hm99-979m?
GHSA-qq4c-hm99-979m is a memory corruption vulnerability in id-map, published on 14 Aug 2025.
Official description
Due to a flaw in the constructor id_map::IdMap::from_iter, ill-formed objects may be created in which the amount of actually initialized memory is less than what is expected by the fields of IdMap. Specifically, the field ids is initialized based on the capacity of the vector values, which is constructed from the provided iterator. However, the length of this vector may be smaller than its capacity.
In such cases, when the resulting IdMap is dropped, its destructor incorrectly assumes that values contains ids.len() == values.capacity() initialized elements and attempts to iterate over and drop them. This leads to dereferencing and attempting to free uninitialized memory, resulting in undefined behavior and potential segmentation faults.
The bug was fixed in commit fab6922, and all unsafe code was removed from the crate.
Note that the maintainer recommends using the following alternatives:
Which versions are affected by GHSA-qq4c-hm99-979m?
3 open source packages ship an affected version, including id-map.
| Package | Affected | Fixed in |
|---|---|---|
id-map crates.io | From 0.1.6 | 0.2.2 |
id-map crates.io | From 0.1.6 | 0.2.2 |
id-map crates.io | From 0.1.6 | 0.2.2 |
How do I fix GHSA-qq4c-hm99-979m?
Upgrade id-map to 0.2.2 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is GHSA-qq4c-hm99-979m being exploited?
There is no known exploitation of GHSA-qq4c-hm99-979m in the wild and no public exploit code.
Sources
Also known as RUSTSEC-2025-0050.