Every CVE Search/ Get API key

CVE-2026-62337

SNARK Verifier: Halo 2 aggregation mishandles point-at-infinity proof elements

6.9 Medium

SNARK Verifier is a generic (S)NARK verifier. Prior to 0.2.5, the Halo 2 aggregation circuit can mishandle proof points encoded as the point at infinity. EcPointLoader::multi_scalar_multiplication places a Value::Assigned(_) base paired with Value::Constant(ONE) into its unscaled variable-base list and passes it directly to sum_with_const. The default shim delegates to halo2-lib EccChip::sum, whose incomplete affine addition assumes nonidentity input points. A prover-controlled proof point encoded as (0, 0) can therefore enter the final aggregation sum through the scalar-one shortcut and affect the MSM or accumulator computation. Practical exploitability depends on the surrounding aggregation and final-decider checks; the advisory does not establish universal acceptance of invalid proofs. 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

0.30%Unchanged since Oct 31, 2026
90%50%10%1%

What each source reports

CVE List Score used 6.9

SNARK Verifier: Halo 2 aggregation mishandles point-at-infinity proof elements

SNARK Verifier is a generic (S)NARK verifier. Prior to 0.2.5, the Halo 2 aggregation circuit can mishandle proof points encoded as the point at infinity. EcPointLoader::multi_scalar_multiplication places a Value::Assigned(_) base paired with Value::Constant(ONE) into its unscaled variable-base list and passes it directly to sum_with_const. The default shim delegates to halo2-lib EccChip::sum, whose incomplete affine addition assumes nonidentity input points. A prover-controlled proof point encoded as (0, 0) can therefore enter the final aggregation sum through the scalar-one shortcut and affect the MSM or accumulator computation. Practical exploitability depends on the surrounding aggregation and final-decider checks; the advisory does not establish universal acceptance of invalid proofs. This issue is fixed in version 0.2.5.

Record
CVE-2026-62337
CVSS 4.0
6.9 MediumCVSS: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
2026-11-02
EUVDEUVD-2026-114436 6.9

SNARK Verifier is a generic (S)NARK verifier. Prior to 0.2.5, the Halo 2 aggregation circuit can mishandle proof points encoded as the point at infinity. EcPointLoader::multi_scalar_multiplication places a Value::Assigned(_) base paired with Value::Constant(ONE) into its unscaled variable-base list and passes it directly to sum_with_const. The default shim delegates to halo2-lib EccChip::sum, whose incomplete affine addition assumes nonidentity input points. A prover-controlled proof point encoded as (0, 0) can therefore enter the final aggregation sum through the scalar-one shortcut and affect the MSM or accumulator computation. Practical exploitability depends on the surrounding aggregation and final-decider checks; the advisory does not establish universal acceptance of invalid proofs. This issue is fixed in version 0.2.5.

Record
EUVD-2026-114436
CVSS 4.0
6.9 MediumCVSS: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
2026-11-02
NVD 6.9

SNARK Verifier is a generic (S)NARK verifier. Prior to 0.2.5, the Halo 2 aggregation circuit can mishandle proof points encoded as the point at infinity. EcPointLoader::multi_scalar_multiplication places a Value::Assigned(_) base paired with Value::Constant(ONE) into its unscaled variable-base list and passes it directly to sum_with_const. The default shim delegates to halo2-lib EccChip::sum, whose incomplete affine addition assumes nonidentity input points. A prover-controlled proof point encoded as (0, 0) can therefore enter the final aggregation sum through the scalar-one shortcut and affect the MSM or accumulator computation. Practical exploitability depends on the surrounding aggregation and final-decider checks; the advisory does not establish universal acceptance of invalid proofs. This issue is fixed in version 0.2.5.

Record
CVE-2026-62337
CVSS 4.0
6.9 MediumCVSS: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
2026-11-03
OSV 6.9

SNARK Verifier: Halo 2 aggregation mishandles point-at-infinity proof elements

SNARK Verifier is a generic (S)NARK verifier. Prior to 0.2.5, the Halo 2 aggregation circuit can mishandle proof points encoded as the point at infinity. EcPointLoader::multi_scalar_multiplication places a Value::Assigned(_) base paired with Value::Constant(ONE) into its unscaled variable-base list and passes it directly to sum_with_const. The default shim delegates to halo2-lib EccChip::sum, whose incomplete affine addition assumes nonidentity input points. A prover-controlled proof point encoded as (0, 0) can therefore enter the final aggregation sum through the scalar-one shortcut and affect the MSM or accumulator computation. Practical exploitability depends on the surrounding aggregation and final-decider checks; the advisory does not establish universal acceptance of invalid proofs. This issue is fixed in version 0.2.5.

Record
CVE-2026-62337
CVSS 4.0
6.9 MediumCVSS: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
2026-11-04

Affected products

History

History
RecordedChangedSources
factsNVD, OSV
first indexedCVE List, EUVD, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-62337 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 0.30%, the 23rd percentile. No source names a fixed version.

References

MoveEnter Open