CVE-2026-27651

CWE-476 — NULL Pointer Dereference11 documents11 sources
Severity
8.7HIGH
EPSS
0.0%
top 87.47%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
2
F5 Nginx Open SourceF5 Nginx Plus
Timeline
PublishedMar 24
Latest updateApr 14

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.

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Affected Packages5 packages

▶CVEListV5f5/nginx_open_source1.29.0 — 1.29.7+1
▶NVDf5/nginx_open_source1.0.0 — 1.28.3+2
▶CVEListV5f5/nginx_plusR36 — R36 P3+4
▶NVDf5/nginx_plusr33 — r35+3
▶Debiannginx< 1.28.3-1

🔴Vulnerability Details

4
VulDB
F5 NGINX Open Source/NGINX Plus Response Header ngx_mail_auth_http_module null pointer dereference (K000160383 / Nessus ID 303484)↗2026-04-14
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GHSA
GHSA-82w2-x7hf-5h8r: 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↗2026-03-24
▶
CVEList
NGINX ngx_mail_auth_http_module vulnerability↗2026-03-24
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OSV
CVE-2026-27651: 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↗2026-03-24
▶

📋Vendor Advisories

4
Red Hat
NGINX: NGINX: Denial of Service via undisclosed requests when ngx_mail_auth_http_module is enabled↗2026-03-24
▶
F5
CVE-2026-27651: When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open Source, undisclosed requests can cau...↗2026-03-24
▶
Microsoft
NGINX ngx_mail_auth_http_module vulnerability↗2026-03-10
▶
Debian
CVE-2026-27651: nginx - When the ngx_mail_auth_http_module module is enabled on NGINX Plus or NGINX Open...↗2026
▶

🕵️Threat Intelligence

1
Wiz
CVE-2026-27651 Impact, Exploitability, and Mitigation Steps | Wiz↗
▶

💬Community

1
Bugzilla
CVE-2026-27651 NGINX: NGINX: Denial of Service via undisclosed requests when ngx_mail_auth_http_module is enabled↗2026-03-24
▶