nginx vulnerabilities

It was discovered that the nginx ngx_mail_auth_http_module module
incorrectly handled certain requests. An attacker could possibly use this
issue to cause nginx to crash, resulting in a denial of service.
(CVE-2026-27651)

It was discovered that the nginx ngx_http_dav_module module incorrectly
handled certain destination URIs. An attacker could use this issue to cause
nginx to crash, resulting in a denial of service, or possibly modify source
or destination names outside of the document root. (CVE-2026-27654)

It was discovered that the nginx ngx_http_mp4_module module incorrectly
handled certain MP4 files. An attacker could use this issue to cause nginx
to crash, resulting in a denial of service, or possibly execute arbitrary
code. (CVE-2026-27784, CVE-2026-32647)

It was discovered that the nginx ngx_mail_smtp_module module incorrectly
handled certain CRLF sequences. An attacker could possibly use this issue
to inject arbitrary SMTP headers. (CVE-2026-28753)

It was discovered that the nginx ngx_stream_ssl_module module incorrectly
handled revoked certificates. This could result in successful TLS
handshakes even after an OCSP check identifies a certificate as revoked,
contrary to expectations. This issue only affected Ubuntu 24.04 LTS and
Ubuntu 25.10. (CVE-2026-28755)