CVE-2026-276517.5HighCWE-476

CVE-2026-27651: NGINX ngx_mail_auth_http_module vulnerability

F5 · NGINX Open Source

Vendor fix available · Affected: F5 NGINX Open Source · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

1.0%probability of exploitation in the next 30 days

62nd percentile

050100

Higher than 62% of scored CVEs

7.5HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products2

From the CVE record. A product or version that is not listed is unknown, not unaffected.

F5 · NGINX Open Sourcefrom 1.29.0 before 1.29.7; from 0.5.15 before 1.28.3
F5 · NGINX Plusfrom R36 before R36 P3; from R35 before R35 P2; R34; R33; from R32 before R32 P5

On the Atlas

Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.

Open the Atlas

Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: NULL Pointer Dereference · Memory Corruption
Vendor: F5
Published: March 2026
Band: Unlikely (under 1%), March 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-27651 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.

References

7 more references are in the CVE record.