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risc0 vulnerable to arbitrary code execution in guest via memory safety failure in `sys_read`

Critical severity GitHub Reviewed Published Oct 1, 2025 in risc0/risc0 • Updated Oct 2, 2025

Package

cargo risc0-aggregation (Rust)

Affected versions

< 0.9

Patched versions

0.9
cargo risc0-zkos-v1compat (Rust)
< 2.1.0
2.1.0
cargo risc0-zkvm (Rust)
< 2.3.2
>= 3.0.0, < 3.0.3
2.3.2
3.0.3
cargo risc0-zkvm-platform (Rust)
< 2.1.0
2.1.0

Description

Arbitrary code execution in guest via memory safety failure in sys_read

In affected versions of risc0-zkvm-platform, when the zkVM guest calls sys_read, the host is able to use a crafted response to write to an arbitrary memory location in the guest. This capability can be leveraged to execute arbitrary code within the guest. As sys_read is the mechanism by which input is requested by the guest, all guest programs built with the affected versions are vulnerable. This critically compromises the soundness guarantees of the guest program.

A fix was applied in #3351. The vulnerable pointer arithmetic was removed, and replaced with a simplified implementation in the v1compat kernel which uses Rust’s slice functions to guarantee memory safety.

The fix has been released as part of risc0-zkvm versions 2.3.2 and 3.0.3. All prior versions are affected.

Remediation

All developers of zkVM applications should update their guests to use risc0-zkvm versions ^2.3.2 or ^3.0.3.

This upgrade can be accomplished by editing all Cargo.toml files in the following way.

  • Any references to risc0-zkvm should use version specifiers ”2.3.2” or ”3.0.3”.
  • Any references to risc0-build should use version specifiers ”2.3.2” or ”3.0.3”, matching risc0-zkvm.
  • Any references to risc0-zkvm-platform should use version specifier ”2.1.0” or later. Most projects will not have direct references to this crate.

Rebuild your application including the guest. You can run the following command to check that the patch is applied:

# Provide the path to your guest Cargo.toml. Should report risc0-zkvm-platform >=v2.1.0
cargo tree --depth 0 -p risc0-zkvm-platform --manifest-path path/to/methods/guest/Cargo.toml

Any applications that use the image ID of this guest need to be updated with the newly built image ID.

Note that there are no changes to the RISC Zero proof system or circuits. Provers are not required to take any action. Users of the Groth16 smart contract verifier and the RISC Zero Verifier Router are not required to take any action beyond updating their guest programs.

Any applications using the risc0-aggregation crate or the RiscZeroSetVerifier smart contract should update to version >=0.9. This application includes a zkVM guest, which is vulnerable in versions prior to 0.9. Instances of the RiscZeroSetVerifier operated by RISC Zero have been disabled via the estop mechanism outlined in the Verifier Management Design.

References

@nategraf nategraf published to risc0/risc0 Oct 1, 2025
Published to the GitHub Advisory Database Oct 1, 2025
Reviewed Oct 1, 2025
Published by the National Vulnerability Database Oct 2, 2025
Last updated Oct 2, 2025

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v4 base metrics

Exploitability Metrics
Attack Vector Network
Attack Complexity Low
Attack Requirements None
Privileges Required None
User interaction None
Vulnerable System Impact Metrics
Confidentiality High
Integrity High
Availability High
Subsequent System Impact Metrics
Confidentiality None
Integrity None
Availability None

CVSS v4 base metrics

Exploitability Metrics
Attack Vector: This metric reflects the context by which vulnerability exploitation is possible. This metric value (and consequently the resulting severity) will be larger the more remote (logically, and physically) an attacker can be in order to exploit the vulnerable system. The assumption is that the number of potential attackers for a vulnerability that could be exploited from across a network is larger than the number of potential attackers that could exploit a vulnerability requiring physical access to a device, and therefore warrants a greater severity.
Attack Complexity: This metric captures measurable actions that must be taken by the attacker to actively evade or circumvent existing built-in security-enhancing conditions in order to obtain a working exploit. These are conditions whose primary purpose is to increase security and/or increase exploit engineering complexity. A vulnerability exploitable without a target-specific variable has a lower complexity than a vulnerability that would require non-trivial customization. This metric is meant to capture security mechanisms utilized by the vulnerable system.
Attack Requirements: This metric captures the prerequisite deployment and execution conditions or variables of the vulnerable system that enable the attack. These differ from security-enhancing techniques/technologies (ref Attack Complexity) as the primary purpose of these conditions is not to explicitly mitigate attacks, but rather, emerge naturally as a consequence of the deployment and execution of the vulnerable system.
Privileges Required: This metric describes the level of privileges an attacker must possess prior to successfully exploiting the vulnerability. The method by which the attacker obtains privileged credentials prior to the attack (e.g., free trial accounts), is outside the scope of this metric. Generally, self-service provisioned accounts do not constitute a privilege requirement if the attacker can grant themselves privileges as part of the attack.
User interaction: This metric captures the requirement for a human user, other than the attacker, to participate in the successful compromise of the vulnerable system. This metric determines whether the vulnerability can be exploited solely at the will of the attacker, or whether a separate user (or user-initiated process) must participate in some manner.
Vulnerable System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the VULNERABLE SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the VULNERABLE SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the VULNERABLE SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
Subsequent System Impact Metrics
Confidentiality: This metric measures the impact to the confidentiality of the information managed by the SUBSEQUENT SYSTEM due to a successfully exploited vulnerability. Confidentiality refers to limiting information access and disclosure to only authorized users, as well as preventing access by, or disclosure to, unauthorized ones.
Integrity: This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information. Integrity of the SUBSEQUENT SYSTEM is impacted when an attacker makes unauthorized modification of system data. Integrity is also impacted when a system user can repudiate critical actions taken in the context of the system (e.g. due to insufficient logging).
Availability: This metric measures the impact to the availability of the SUBSEQUENT SYSTEM resulting from a successfully exploited vulnerability. While the Confidentiality and Integrity impact metrics apply to the loss of confidentiality or integrity of data (e.g., information, files) used by the system, this metric refers to the loss of availability of the impacted system itself, such as a networked service (e.g., web, database, email). Since availability refers to the accessibility of information resources, attacks that consume network bandwidth, processor cycles, or disk space all impact the availability of a system.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(26th percentile)

Weaknesses

Improper Control of Generation of Code ('Code Injection')

The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment. Learn more on MITRE.

CVE ID

CVE-2025-61588

GHSA ID

GHSA-jqq4-c7wq-36h7

Source code

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