How severe is GHSA-g3qg-6746-3mg9?

No CVSS score has been assigned to GHSA-g3qg-6746-3mg9 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-g3qg-6746-3mg9?

GHSA-g3qg-6746-3mg9 affects the following packages: risc0-zkvm (crates.io), risc0-circuit-rv32im (crates.io). Ecosystems affected: crates.io.

How do I fix GHSA-g3qg-6746-3mg9?

Update risc0-zkvm to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g3qg-6746-3mg9 is resolved across your whole dependency graph.

How do I detect GHSA-g3qg-6746-3mg9 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for risc0-zkvm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-g3qg-6746-3mg9 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Is GHSA-g3qg-6746-3mg9 actively exploited in the wild?

No public exploit code has been indexed for GHSA-g3qg-6746-3mg9 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-g3qg-6746-3mg9?

GHSA-g3qg-6746-3mg9 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 19th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-g3qg-6746-3mg9?

GHSA-g3qg-6746-3mg9 is classified as CWE-345 (CWE-345). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-g3qg-6746-3mg9 published, and has it been updated?

GHSA-g3qg-6746-3mg9 was published on June 20, 2025 and was last updated on June 27, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

zkVM Underconstrained Vulnerability

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-g3qg-6746-3mg9.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs19th percentile — riskier than 19% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

🦀risc0-zkvm🦀risc0-circuit-rv32im

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.

Description

Due to a missing constraint in the rv32im circuit, any 3-register RISC-V instruction (including remu and divu) in risc0-zkvm 2.0.0, 2.0.1, and 2.0.2 are vulnerable to an attack by a malicious prover. The main idea for the attack is to confuse the RISC-V virtual machine into treating the value of the rs1 register as the same as the rs2 register due to a lack of constraints in the rv32im circuit.

This vulnerability was reported by Christoph Hochrainer via our Hackenproof bug bounty. We have evaluated the severity of the vulnerability as “Critical,” and paid a bounty.

The fix for the circuit was implemented in zirgen/pull/238, and the update to risc0 was implemented in risc0/pull/3181. Impacted on-chain verifiers have already been disabled via the estop mechanism outlined in the Verifier Management Design.

Mitigation

We recommend all impacted users upgrade as soon as possible.

Rust applications using the risc0-zkvm crate at versions 2.0.0, 2.0.1, and 2.0.2 should upgrade to version 2.1.0.

Smart contract applications using the official RISC Zero Verifier Router do not need to take any action: zkVM version 2.1 is active on all official routers, and version 2.0 has been disabled.

Smart contract applications not using the verifier router should update their contracts to send verification calls to the 2.1 version of the verifier.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`risc0-zkvm`	≥ 2.0.0&&< 2.1.0	2.1.0`cargo update -p risc0-zkvm --precise 2.1.0`
🦀crates.io	`risc0-circuit-rv32im`	≥ 2.0.0&&< 2.0.4	2.0.4`cargo update -p risc0-circuit-rv32im --precise 2.0.4`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for risc0-zkvm, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update risc0-zkvm to 2.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-g3qg-6746-3mg9 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

Due to a missing constraint in the rv32im circuit, any 3-register RISC-V instruction (including remu and divu) in risc0-zkvm 2.0.0, 2.0.1, and 2.0.2 are vulnerable to an attack by a malicious prover. The main idea for the attack is to confuse the RISC-V virtual machine into treating the value of the rs1 register as the same as the rs2 register due to a lack of constraints in the rv32im circuit. This vulnerability was reported by Christoph Hochrainer via our Hackenproof bug bounty. We have evaluated the severity of the vulnerability as “Critical,” and paid a bounty. The fix for the circuit w

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zkVM Underconstrained VulnerabilityGHSA-g3qg-6746-3mg9