RUSTSEC-2026-0207 Incorrect Output of Incremental Portable SHAKE API on Multiple Squeeze Calls
Incorrect output generation in the portable SHAKE API when squeezing in multiple calls can lead to data integrity issues for dependent applications.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- Available
What is RUSTSEC-2026-0207?
RUSTSEC-2026-0207 is a vulnerability in libcrux-sha3, published on 22 Apr 2026.
Official description
The incremental squeeze functions in the portable SHAKE XOF API, when
attempting to squeeze an output using multiple calls to squeeze,
rather than squeezing the full output at once, could output incorrect
values. Internally, output blocks that were not completely squeezed
were not buffered for the next call to squeeze, which would
consequently drop bytes of the correct squeeze output if the preceding
call requested an output of length in bytes not cleanly divisible by
RATE (168 for SHAKE128, 136 for SHAKE256).
Impact
This bug impacts users that rely on this XOF API to squeeze output in
multiple calls where any of the calls request an output length that is
not divisible by RATE. It does not impact the use of libcrux-sha3 in
libcrux-ml-kem or libcrux-ml-dsa.
Mitigation
Starting from version 0.0.10 the squeeze functions correctly output
all squeezed bytes independent of the number of squeeze calls and
the output lengths requested in each call.
Which versions are affected by RUSTSEC-2026-0207?
1 open source package ship an affected version, including libcrux-sha3.
| Package | Affected | Fixed in |
|---|---|---|
libcrux-sha3 crates.io | From 0.0.0-0 | 0.0.10 |
How do I fix RUSTSEC-2026-0207?
Upgrade libcrux-sha3 to 0.0.10 or later.
Is RUSTSEC-2026-0207 being exploited?
There is no known exploitation of RUSTSEC-2026-0207 in the wild and no public exploit code.