SB20260325200 - Fedora 44 update for nginx, nginx-mod-brotli, nginx-mod-fancyindex, nginx-mod-headers-more, nginx-mod-modsecurity, nginx-mod-naxsi, nginx-mod-vts
Published: March 25, 2026 Updated: May 22, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 6 vulnerabilities.
1) Heap-based buffer overflow (CVE-ID: CVE-2026-27654)
CWE-ID: CWE-122 - Heap-based Buffer Overflow
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:P/U:Green
The vulnerability allows a remote attacker to perform a denial of service attack.
The vulnerability exists due to a boundary error in the ngx_http_dav_module module. A remote attacker can send specially crafted request to the server, trigger a heap-based buffer overflow and perform a denial of service attack or modify source or destination file names outside the document root.
2) Integer overflow (CVE-ID: CVE-2026-27784)
CWE-ID: CWE-190 - Integer overflow
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to integer overflow in the ngx_http_mp4_module module. A remote attacker can supply specially crafted MP4 data to the server, trigger an integer overflow and execute arbitrary code on the target system.
Note, the vulnerability affects only 32-bit NGINX Open Source deployments.
3) Out-of-bounds write (CVE-ID: CVE-2026-32647)
CWE-ID: CWE-787 - Out-of-bounds write
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
The vulnerability allows a remote attacker to compromise vulnerable system.
The vulnerability exists due to a boundary error in the ngx_http_mp4_module module. A remote attacker can supply a specially crafted MP4 file to the server, trigger an out-of-bounds write and execute arbitrary code on the target system.
4) NULL pointer dereference (CVE-ID: CVE-2026-27651)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error within the ngx_mail_auth_http_module module. A remote attacker can send specially crafted request to the server and perform a denial of service (DoS) attack.
Successful exploitation of the vulnerability requires that the CRAM-MD5 or APOP authentication is enabled, and the authentication server permits retry by returning the Auth-Wait response header.
5) CRLF injection (CVE-ID: CVE-2026-28753)
CWE-ID: CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to inject arbitrary data in server response.
The vulnerability exists due to insufficient validation of attacker-supplied data in the ngx_mail_smtp_module module when handling DNS responses. A remote attacker can inject arbitrary headers into SMTP upstream requests and manipulate data.
6) Incorrect authorization (CVE-ID: CVE-2026-28755)
CWE-ID: CWE-863 - Incorrect Authorization
CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
The vulnerability allows a remote attacker to bypass implemented security restrictions.
The vulnerability exists due to improper handling of revoked certificates in the ngx_stream_ssl_module module when configured with the ssl_verify_client on and ssl_ocsp on directives. A remote attacker can bypass authorization checks and access application data with a revoked certificate.
Remediation
Install update from vendor's website.