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GHSA-xrf2-5r3p-5wgj json

libcrux: Panic in Signature Hint Decoding During Verification

published 8mo ago modified 7mo ago also RUSTSEC-2026-0076

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
—
no score, EPSS covers CVEs only
public exploits
0
none known

Summary

During ML-DSA verification the serialized hint values are decoded as specified in algorithm 22 `HintBitUnpack` of [FIPS 204, subsection 7.1](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.204.pdf#%5B%7B%22num%22%3A120%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22FitH%22%7D%2C657%5D). The algorithm requires that the cumulative hint counters per row of the hint vector are strictly increasing and below a maximum value which depends on the choice of ML-DSA parameter set (line 4).

In libcrux-ml-dsa, hint decoding did not check the boundedness of the cumulative hint counter of the last row of the hint vector.

## Impact A manipulated invalid hint can cause an out-of-bounds memory access since the hint decoding logic may attempt to read outside the bounds of the serialized signature, causing a runtime panic.

## Mitigation Starting from version `0.0.8`, hint decoding will check the cumulative hint counter of the last row as well.

Patch / fix

  • crates.io libcrux-ml-dsa 0.0.8

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Affected packages

ecosystem package affected fixed in
crates.io libcrux-ml-dsa
<0.0.8
>=0.0.0-0, <0.0.8
0.0.8

Classification

Weakness
  • CWE-125 Out-of-bounds Read
  • CWE-1285 Improper Validation of Specified Index, Position, or Offset in Input

References

Sources

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