Is CVE-2026-27651 actively exploited?

No active exploitation of CVE-2026-27651 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-27651 be exploited remotely?

Yes. CVE-2026-27651 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-27651?

CVE-2026-27651 has a CVSS score of 7.5 (HIGH).

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HIGH

CVE-2026-27651

CWE-476Published: March 24, 2026· Updated: Mar 30, 2026

7.5

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:9.0th

Official Description

When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cause worker processes to terminate. This issue may occur when (1) CRAM-MD5 or APOP authentication is enabled, and (2) the authentication server permits retry by returning the Auth-Wait response header. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

NVD Source

Technical Analysis

CVE-2026-27651 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.