CVE-2026-92595 nodemailer CVE debrief

Who should care

Defenders responsible for applications using Nodemailer should assess exposure and prioritize upgrading to version 9.1.1 or later. They should also review and restrict usage of the `MailMessage.resolveContent()` API, especially with untrusted message content.

Why it matters

CVE-2026-92595 allows for sandbox bypass in Nodemailer versions 9.1.0 and earlier via the `MailMessage.resolveContent()` API. Defenders should verify if their applications use vulnerable versions and upgrade to version 9.1.1 or later. They should also review and restrict usage of the `MailMessage.resolveContent()` API, especially with untrusted message content.

• Potential for reading arbitrary local files
• Potential for issuing outbound HTTP(S) requests
• Bypassing of sandbox restrictions
• Verification of Nodemailer version and API usage required

Technical summary

Nodemailer versions 9.1.0 and earlier do not honor the `disableFileAccess` and `disableUrlAccess` sandbox options when message content is resolved through the public plugin API `MailMessage.resolveContent()` using the documented legacy three-argument signature. This allows plugin or application code to read arbitrary local files or issue outbound HTTP(S) requests, bypassing the sandbox. The internal paths used by `transporter.sendMail()` are not affected. The vulnerability can be mitigated by upgrading to version 9.1.1 or later and restricting usage of the `MailMessage.resolveContent()` API.

Defensive priority

Defenders should prioritize verifying if their applications use vulnerable Nodemailer versions and upgrading to version 9.1.1 or later. They should also review and restrict usage of the `MailMessage.resolveContent()` API, especially with untrusted message content.

Recommended defensive actions

• Verify if applications use vulnerable Nodemailer versions
• Upgrade to Nodemailer version 9.1.1 or later
• Review and restrict usage of the `MailMessage.resolveContent()` API
• Monitor for suspicious activity related to Nodemailer usage
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details on the vulnerability in Nodemailer versions 9.1.0 and earlier. The vulnerability allows plugin or application code to read arbitrary local files or issue outbound HTTP(S) requests, bypassing the sandbox.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.