Bug 2567537 (CVE-2026-61618) - CVE-2026-61618 snark-verifier: snark-verifier: Denial of Service via non-canonical accumulator limb decoding
Summary: CVE-2026-61618 snark-verifier: snark-verifier: Denial of Service via non-cano...
Keywords:
Status: NEW
Alias: CVE-2026-61618
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
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Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-11-05 22:05 UTC by OSIDB Bzimport
Modified: 2026-11-05 23:04 UTC (History)
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Description OSIDB Bzimport 2026-11-05 22:05:41 UTC
SNARK Verifier is a generic (S)NARK verifier. Prior to 0.2.5, KZG accumulator public-instance limbs are decoded without consistently enforcing canonical limb bounds before elliptic-curve coordinate reconstruction. `PlonkProof::read` selects scalars using `accumulator_indices` and passes them to `AccumulatorEncoding::from_repr`. For the EVM loader, `LimbsEncoding::from_repr` forwards them to `EvmLoader::ec_point_from_limbs` in `snark-verifier/src/loader/evm/loader.rs`, where `shl` and `add` reconstruct coordinates before `validate_ec_point` checks the resulting affine point rather than the original limb bounds. The related native path in `snark-verifier/src/pcs/kzg/accumulator.rs` can reach assertion- or unwrap-based decoding and panic instead of returning a verification error. This allows noncanonical encodings at the verifier boundary and can crash the native verifier. Standard SDK aggregation circuits are expected to constrain accumulator limbs before this boundary, which limits practical exploitability. This issue is fixed in version 0.2.5.


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