On October 8, 2026, Anthropic announced that it was making OSS Scanner available to more open-source projects: eligible projects can opt in to periodic vulnerability scans at no cost. Anthropic models, including Claude Mythos, generate the reports, which reach maintainers without human review or triage.
What the reports contain—and who reviews them
A report may include a reproducible example of the issue, an explanation, a bisection to help identify when a bug entered the project when possible, and a candidate patch when available. A candidate patch is a proposed fix, not a guarantee that the issue has been resolved.
Anthropic says its models generate reports without human review or triage before delivery. Triage means sorting and prioritizing findings; here, maintainers receive the reports without that human step. Anthropic also cautions that findings may be incorrect or invalid, so maintainers must assess them before deciding what to do.
Scans are periodic, and their frequency may depend on the number of projects in the pipeline and on project use.
How a project can apply
A core maintainer requests enrollment by opening a pull request that adds a project configuration. Anthropic checks the applicant’s maintainer status and assesses eligibility case by case. Its criteria are similar to OSS-Fuzz and include the project’s impact on infrastructure and user security, exposure to remote attacks, and the number of users or projects that depend on it.
The configuration includes the Git repository, a primary contact email, and the path to a Dockerfile that prepares and builds the project for scanning. The repository can be hosted outside GitHub. Anthropic uses the Dockerfile build to prepare the project for an offline audit by its agents.
What Anthropic’s reviewed sample found
Anthropic reported that penetration testers reviewed 97 critical- and high-severity findings across 48 projects. Of those, 85 met its bar for coordinated vulnerability disclosure (CVD), the process for validating and responsibly handling vulnerability reports. Anthropic reported that as 88%; 11 other findings were real but duplicated known issues or other scan findings, and one was invalid.
| Outcome in the reviewed sample | Findings |
| Met Anthropic’s CVD bar | 85 (88%) |
| Real duplicates | 11 |
| Invalid | 1 |
These counts describe the selected review sample, not a general accuracy measure for every OSS Scanner report.
How scans and reports are handled
Anthropic says the Dockerfile build has network access, while agents perform their audit work afterward in hardened sandboxes without internet access. The company also says reports are stored in an isolated, locked-down cloud project, accessible to security staff who need them to develop and operate the program.
Unvalidated OSS Scanner reports are not subject to a 90-day disclosure period. If Anthropic later validates a report manually through its CVD program, its policy may permit disclosure beginning 90 days after the maintainer is notified of that validation.
