Issues

• Function-contract model validation fails for a constant-returning boolean function — Kani 0.68.0 / CBMC 6.11.0

  [C] Bug
  model-checking/kani#5097 · Filter by author Egly443 opened on Oct 29, 2026

• #[kani::solver(bitwuzla)] verifies false assertions on checked arithmetic (diffblue/cbmc#9144)

  model-checking/kani#5096 · Filter by author abdou-rgd opened on Oct 29, 2026

• #[kani::stub] silently not applied to MIR-inlined calls (opt-level 2/3): false proofs

  model-checking/kani#5094 · Filter by author r-near opened on Oct 28, 2026

• --cbmc-args --show-properties panics in cbmc_output_parser

  model-checking/kani#5091 · Filter by author r-near opened on Oct 28, 2026

• kani panics when getting ABI for let _: [u8; usize::MAX] = kani::any()

  [C] Bug
  model-checking/kani#5090 · Filter by author datdenkikniet opened on Oct 28, 2026
  1

• Constant read from a static's storage when their initial bytes match: false proofs

  model-checking/kani#5088 · Filter by author r-near opened on Oct 28, 2026

• Automatic Charon upgrade failed

  model-checking/kani#5086 · Filter by author github-actions opened on Oct 28, 2026

• CBMC invariant failure (bits2expr) on a static/const whose type contains an array of zero-sized arrays

  model-checking/kani#5085 · Filter by author JeroenRobben opened on Oct 27, 2026

• f16::NEG_INFINITY as i32/i64/i128/isize is not saturated to MIN (Kani proves it equals 0)

  model-checking/kani#5084 · Filter by author JeroenRobben opened on Oct 27, 2026

• Kani does not check the 0/!0 lane precondition of simd_reduce_all

  model-checking/kani#5083 · Filter by author JeroenRobben opened on Oct 27, 2026

• unchecked_shl/unchecked_shr on a 128-bit integer with an i8 distance always fails "excessive shift distance"

  model-checking/kani#5082 · Filter by author JeroenRobben opened on Oct 27, 2026

• Kani reports "attempt to compute simd_add which would overflow" for wrapping SIMD arithmetic (_mm_add_epi8, std::simd +)

  model-checking/kani#5081 · Filter by author JeroenRobben opened on Oct 27, 2026

• NaN results of float arithmetic are modelled as a signaling NaN (0x7ff0000000000001), so Kani proves false properties about to_bits()

  model-checking/kani#5080 · Filter by author JeroenRobben opened on Oct 27, 2026

• C library model: powf/powi/exp/ln models exclude the real result: Kani proves 1.1f64.powf(1.0) != 1.1 and 3.0f64.powi(2) != 9.0

  model-checking/kani#5079 · Filter by author JeroenRobben opened on Oct 27, 2026

• Constant-folded floating-point division misrounds false ties: 1.0 / 0.49999999999999994 evaluates to 2.0

  model-checking/kani#5078 · Filter by author JeroenRobben opened on Oct 27, 2026

• Kani types a #[repr(C)] enum with data at 5 bytes instead of 8: pointer arithmetic over [E; N] reads the wrong element and a failing assertion is proved

  model-checking/kani#5077 · Filter by author JeroenRobben opened on Oct 27, 2026

• Misaligned ptr::read / ptr::write (and <*const T>::read, NonNull::read) are not reported; VERIFICATION SUCCESSFUL on UB

  model-checking/kani#5076 · Filter by author JeroenRobben opened on Oct 27, 2026

• Niche value for a later variant is not reduced modulo the tag width, so a false assertion on the tag byte verifies and matches! crashes CBMC

  model-checking/kani#5075 · Filter by author JeroenRobben opened on Oct 27, 2026

• Kani reads the dyn Trait tail field of a struct at its static offset: false proof for &W<dyn G>, false alarm for Rc<dyn G> with over-aligned values

  model-checking/kani#5074 · Filter by author JeroenRobben opened on Oct 27, 2026

• Spurious dereference failure for ptr::read_volatile on a zero-sized type

  model-checking/kani#5072 · Filter by author Tiramisu-Cake opened on Oct 27, 2026

• Unsound and spurious results for copy_from_slice / copy_nonoverlapping when a slice may point to one of two arrays of different sizes (CBMC diffblue/cbmc#9237)

  model-checking/kani#5065 · Filter by author frederickjjoubert opened on Oct 26, 2026

• Toolchain upgrade to nightly-2026-10-24 failed

  model-checking/kani#5061 · Filter by author github-actions opened on Oct 25, 2026

• -Z valid-value-checks reports invalid values during initialization and raw field-address formation

  [C] Bug
  model-checking/kani#5056 · Filter by author v3risec opened on Oct 23, 2026
  2

• Support libc strlen through CBMC's built-in model without -Z c-ffi

  model-checking/kani#5055 · Filter by author feliperodri opened on Oct 23, 2026

• Loop contracts: a write missing from loop_modifies is accepted at -Zmir-opt-level=2 (the kani_loop_modifies binding is optimized out)

  [C] Bug
  model-checking/kani#5053 · Filter by author kasimte opened on Oct 23, 2026