Anthropic's coordinated vulnerability disclosure dashboard

Last updated 2026-08-26 11:55 PT.

In February 2026, Anthropic began using an early snapshot of Claude Mythos Preview to find security vulnerabilities in open-source software. We then partnered with external security research firms to triage findings, validate them, and report human-reviewed critical- or high-severity vulnerabilities to the software's maintainers under our Coordinated Vulnerability Disclosure policy. This page tracks the findings that we've disclosed, and, in line with our policy, publishes details of the ones whose disclosure window has now closed.

As of August 26, 2026, we've disclosed 2,300 vulnerabilities across 392 open source projects. To our knowledge, 421 of these have been patched. Across all findings in the ledger, 462 identifiers have been issued: 177 CVE records and 285 GitHub Security Advisories (a single finding may carry both). In other cases, maintainers have shipped a fix without publishing an advisory. The number of vulnerabilities we've disclosed is a subset of the total number of vulnerabilities that Mythos Preview (and other Claude models) has found, since the process of independent human triage and review is the rate limiting step.

This page covers a headline count of the vulnerabilities we've disclosed, and a breakdown of these by class. For those vulnerabilities we've disclosed and where the disclosure window has now closed, it also includes identifier records (CVE & GHSA) and finding details, further below.

Finally, it includes a disclosure ledger, which lists a hash commitment for every finding we've disclosed that is still inside the disclosure window, so that the finding's existence and commitment date can be proved without revealing its content.

Once a finding has been validated by one of our external security research firms, a SHA-3-512 hash of the sealed report is published immediately as proof of possession. Each ledger entry shows more detail as it progresses through disclosure: before the maintainer has been notified, only the commitment hash and the commitment date are published; once the report has been sent, the status and the severity assessments are shown and the discovery date is published (it drives the date filter); and the identifier, project, and bug class are revealed only when the disclosure window closes. A commitment that is withdrawn at any stage keeps its hash and commitment date and is marked withdrawn in the status column; a commitment withdrawn before the finding was revealed is also struck through in the table.

Common Vulnerabilities and Exposures records assigned to findings disclosed through this program. The records below are publicly available. The remainder are reserved, pending publication by the assigning authority.

GitHub Security Advisory records assigned to findings disclosed through this program. The records below are publicly available. The remainder are reserved, pending publication by the assigning authority.

This graph compares Claude's initial severity assessments against the external security research firms' assessments, for those findings that have completed triage. Cells on the diagonal indicate agreement. The number assessed here represents the subset of vulnerabilities included on our disclosure ledger that were reviewed by our security partners, rather than disclosed by us directly.

Anthropic's severity assessments are produced before any maintainer input. Project maintainers often apply project-specific severity rules that Claude does not have access to at run time, so what one maintainer rates as critical another may rate as low. The external security research firms incorporate that context, which is why their assessments tend to be lower.

This snapshot was generated on 2026-08-26 11:55 PT. The manifest hash below is the SHA-3-512 hash of the structured payload and is republished with every dated snapshot so any figure on this page can be verified against the machine-readable record.

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