CVE-2026-61618
SNARK Verifier: noncanonical accumulator limb decoding
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.
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
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
6.9
SNARK Verifier: noncanonical accumulator limb decoding
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.
- Record
CVE-2026-61618- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-20
- Updated
- 2026-11-05
EUVDEUVD-2026-114397
6.9
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.
- Record
EUVD-2026-114397- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-05
NVD
6.9
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.
- Record
CVE-2026-61618- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Weakness
- CWE-20
- Updated
- 2026-11-05
OSV
6.9
SNARK Verifier: noncanonical accumulator limb decoding
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.
- Record
CVE-2026-61618- CVSS 4.0
- 6.9 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-20
- Updated
- 2026-11-05
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | NVD, OSV | |
| first indexed | CVE List, EUVD, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-61618 is a medium vulnerability (CVSS 6.9) in Axiom-crypto Snark-verifier, published October 30, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 31st percentile. No source names a fixed version.
References
github.com/axiom-crypto/snark-verifier/security/advisories/GHSA-265x-v3qf-ff6p
github.com/axiom-crypto/snark-verifier/commit/d6aaf66d4706f5317cf61d5dbe00c14e7fbdbb70
github.com/axiom-crypto/snark-verifier/releases/tag/v0.2.5
github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61618.json
nvd.nist.gov/vuln/detail/CVE-2026-61618