CVE-2026-82854
SMTP command injection via unsanitized envelope.size in Nodemailer <8.0.4
Is CVE-2026-82854 being exploited?
Not confirmed. CVE-2026-82854 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 1.1% probability of exploitation in the next 30 days.
How severe is CVE-2026-82854?
CVE-2026-82854 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-82854?
Yes. A fix has been recorded for CVE-2026-82854. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-82854 affect?
CVE-2026-82854 affects Nodemailer < 8.0.4, Node.js apps that pass custom envelope.size, Email services using Nodemailer. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-82854?
Upgrade to Nodemailer >=8.0.4 and sanitize/validate envelope.size to remove CRLF
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
CRLF injection in envelope.size lets attacker inject SMTP commands (e.g., RCPT TO) to add silent recipients, alter mail flow, enable data exfiltration or spam.
Immediate action required
- affected< 8.0.3
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.