Anthropic's Responsible Disclosure Policy: How Glasswing CVD Works in Practice

Project Glasswing operates under a coordinated vulnerability disclosure model consistent with ISO/IEC 29147 and FIRST.org's CVD guidelines. The core principle is private notification first, public disclosure after remediation. Anthropic notifies affected vendors privately, provides technical details sufficient to reproduce and fix the vulnerability, and gives vendors a defined remediation window before any public disclosure. The model prioritizes giving defenders time to patch before attackers can exploit a published advisory.

Notification goes to the security contact registered with CERT/CC, the vendor's published security advisory email (security@, psirt@, or equivalent), or the contact on file with the CVE program if the vendor is a CNA. For open source projects without a dedicated security contact, Glasswing may route through the project's primary maintainers or through a relevant CERT. Notification happens when Glasswing has sufficient confidence in a finding and has completed internal triage. The disclosure clock starts at the date of the initial notification, not at the date of vendor acknowledgment.

The standard Glasswing disclosure timeline: Day 0 is initial private notification with technical details. Day 5 is the vendor acknowledgment deadline. Days 5 to 30 are the patch development window for straightforward fixes. Day 90 is the default public disclosure date if no extension has been granted. For critical vulnerabilities with active exploitation evidence, Glasswing may compress the timeline and coordinate with CISA on emergency notification. For complex vulnerabilities requiring multi-vendor coordination (such as protocol-level flaws affecting multiple implementations), the timeline is negotiated with all affected parties.

When you receive a Glasswing notification, your expected actions are: acknowledge receipt within five business days and assign a named security contact, provide a realistic patch timeline within 30 days of notification, communicate blockers or dependencies that affect the timeline early, test and validate the fix before the disclosure date, and prepare a public advisory or CVE annotation for coordinated release. You are not obligated to patch within any specific window below 90 days, but a vendor that has not responded is not eligible for timeline extensions.

Anthropic operates as a CVE Numbering Authority (CNA) for Project Glasswing discoveries. As a CNA, Anthropic can reserve CVE IDs directly from the CVE program's block allocation and assign them to confirmed vulnerabilities without waiting for MITRE review. This streamlines the process for straightforward cases. For vulnerabilities requiring multi-vendor coordination or cross-product scope (such as a flaw in a shared library used across dozens of products), Anthropic may work with CERT/CC or CISA as additional coordinating CNAs. CVE IDs are reserved at the time of vendor notification and published at the time of public disclosure.

If a vendor does not respond to notification within the acknowledgment window, Glasswing sends a second notification and attempts contact through alternate channels (additional email contacts, CERT/CC coordination, LinkedIn or conference contacts for open source maintainers). If no response is received by day 45, the vulnerability proceeds to public disclosure at day 90 regardless of patch status. Glasswing will note in the public advisory that notification was delivered and unacknowledged. CISA may be involved in parallel for critical infrastructure vendors who are unresponsive.

CERT/CC at Carnegie Mellon serves as a neutral coordinator for cases where direct vendor contact is not possible, where multiple vendors are affected, or where a vendor disputes Glasswing's findings. CISA serves a similar role for US critical infrastructure operators. For vulnerabilities affecting critical infrastructure sectors (energy, water, healthcare, financial services), Glasswing coordinates with CISA in parallel with vendor notification. CISA's involvement does not extend the disclosure deadline but can provide additional remediation support resources to affected organizations.

CVE-2026-4747 in FreeBSD illustrates the standard timeline: private notification to the FreeBSD Security Team, acknowledgment within two business days, patch developed and integrated into a security advisory, coordinated public release at 90 days. CVE-2026-5194 in wolfSSL (CVSS 9.1) required additional coordination because the certificate validation flaw affected downstream products built on wolfSSL. The disclosure was extended to allow wolfSSL to notify major downstream integrators before the public advisory was published. Both cases resulted in a published CVE advisory, vendor patch notes, and a Glasswing technical writeup.

At the time of coordinated public disclosure, Glasswing publishes a technical advisory that includes the CVE identifier, affected versions, vulnerability description, proof-of-concept (where appropriate), CVSS score and vector, remediation guidance, and a timeline of the disclosure process. The advisory is published on Anthropic's security portal and submitted to the NVD for inclusion in the CVE database. Vendors are encouraged to publish their own advisory in parallel and to reference the CVE identifier in patch notes.

The complete vendor response playbook, including response templates for Glasswing notifications, internal escalation paths, legal and communications considerations for public disclosure, and the contact escalation guide for cases where Glasswing coordination stalls, is available in the Mythos Brief.