RUSTSEC-2026-0207
Incorrect Output of Incremental Portable SHAKE API on Multiple Squeeze Calls
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
What each source reports
OSV Score used
Incorrect Output of Incremental Portable SHAKE API on Multiple Squeeze Calls
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.
- Record
RUSTSEC-2026-0207- CVSS 4.0
- 8.2 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
Affected packages
| Package | Affected | Fixed |
|---|---|---|
libcrux-sha3crates.io |
0.0.0-0 up to 0.0.10 | 0.0.10 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
RUSTSEC-2026-0207 is a high vulnerability (CVSS 8.2) in libcrux-sha3, published April 22, 2026. No source lists public exploit code. Fixed in libcrux-sha3 0.0.10.