OpenVM Halo2 Solidity verifier: Proof verification bypass via self-call
Summary
The Solidity verifier wrapper generated by OpenVM can be tricked into treating a successful internal call as proof acceptance. If the first four proof bytes match another external function selector of the wrapper, an attacker can have a non-verifier function accepted instead of the Halo2 verifier. Applications using the generated wrapper may then accept arbitrary app commitments and public values without valid proof checks.
Affected
- OpenVM before 1.7.0 (1.x line)
- OpenVM 2.0.0-alpha to before 2.0.0-rc.3
- OpenVM 2.1.0-dev.0 to before 2.1.0-preview
- Note: the affected ranges are taken from the CVE record; the vendor advisory was not directly confirmed.
Fixed in
- OpenVM 1.7.0
- OpenVM 2.0.0-rc.3
- OpenVM 2.1.0-preview
Workaround
Unknown.
Exploitation
- No evidence of exploitation in the wild found as of 31 Oct 2026.
- No public proof of concept found for this CVE.
- CISA SSVC: exploitation none, automatable yes, technical impact partial.
Our recommendation
- Check whether OpenVM is used in any on-chain or zero-knowledge application, including test networks.
- Identify deployed verifier contracts and the OpenVM version that generated them.
- Upgrade to 1.7.0, 2.0.0-rc.3 or 2.1.0-preview, then regenerate and redeploy affected verifier contracts.
- Review whether applications trust the verifier result without further checks.
- Relevance for typical SME IT environments is low.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE-2026-62334 Official record (vuldb) vuldb.com
- OpenVM security advisories github.com
- OpenVM release v1.7.0 github.com
- OpenVM release v2.0.0-rc.3 github.com
- OpenVM release v2.1.0-preview github.com
- OpenVM fix commit github.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 23:18.
Original description (NVD)
OpenVM is a performant and modular zkVM framework built for customization and extensibility. Before 1.7.0 in the 1.x line and in affected 2.0 and 2.1 prereleases, `OpenVmHalo2Verifier.verify` constructs raw proof calldata from user-controlled `proofData`, performs a `staticcall` to `address(this)`, and treats a successful call as proof acceptance. If the first four proof bytes match another external selector exposed by the wrapper, dispatch can invoke a successful non-verifier function instead of the generated Halo2 fallback verifier. Applications using the generated Solidity wrapper can consequently accept arbitrary app commitments and public values without checking the proof suffix, accumulator, app commitments or public values. This issue is fixed in versions 1.7.0, 2.0.0-rc.3 and 2.1.0-preview.
NVD references (9)
- https://github.com/openvm-org/openvm/blob/v2.0.0-alpha/crates/sdk/contracts/template/OpenVmHalo2Verifier.sol
- https://github.com/openvm-org/openvm/blob/v2.0.0-beta.2/crates/sdk/contracts/template/OpenVmHalo2Verifier.sol
- https://github.com/openvm-org/openvm/blob/v2.1.0-dev.0/crates/sdk/contracts/template/OpenVmHalo2Verifier.sol
- https://github.com/openvm-org/openvm/commit/751bdb1725254c3268782ddf8df89f19035666e3
- https://github.com/openvm-org/openvm/pull/151
- https://github.com/openvm-org/openvm/releases/tag/v1.7.0
- https://github.com/openvm-org/openvm/releases/tag/v2.0.0-rc.3
- https://github.com/openvm-org/openvm/releases/tag/v2.1.0-preview
- https://github.com/openvm-org/openvm/security/advisories/GHSA-j29p-wr24-hp4f
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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