Vulnerability in F5 NGINX Plus

[ Description ]Official description

A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and the root directive or access log format references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Impact:  This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

[ Fixes ]Fixes and patches

• Security bulletin: F5 K000162613Vendor patch or bulletin · CERT-FR · my.f5.com/manage/s/article/K000162613, cited by CERT-FR CERTFR-2026-AVI-1317
• Security bulletin: F5 K000162606Vendor patch or bulletin · CERT-FR · my.f5.com/manage/s/article/K000162606, cited by CERT-FR CERTFR-2026-AVI-1317
• Security bulletin: F5 K000162416Vendor patch or bulletin · CERT-FR · my.f5.com/manage/s/article/K000162416, cited by CERT-FR CERTFR-2026-AVI-1317
• Security bulletin: F5 K000162607Vendor patch or bulletin · CERT-FR · my.f5.com/manage/s/article/K000162607, cited by CERT-FR CERTFR-2026-AVI-1317
• Security bulletin: F5 K000162608Vendor patch or bulletin · CERT-FR · my.f5.com/manage/s/article/K000162608, cited by CERT-FR CERTFR-2026-AVI-1317

[ Advisories ]Government CERT advisories

• CERT-FR19 Oct 2026CERTFR-2026-AVI-1341

  Multiple vulnerabilities in F5 products Translated from French

  Multiple vulnerabilities have been discovered in F5 products. Some of them allow an attacker to cause remote arbitrary code execution, remote denial of service and a breach of data confidentiality.

  CVE-2026-91184CVE-2026-101019CVE-2026-96615+8 more CVEs
• CERT-FR15 Oct 2026CERTFR-2026-AVI-1317

  Multiple vulnerabilities in F5 products Translated from French

  Multiple vulnerabilities have been discovered in F5 products. Some of them allow an attacker to cause remote arbitrary code execution, a breach of data confidentiality and a breach of data integrity.

  CVE-2026-15176CVE-2026-97205CVE-2026-95101+2 more CVEs
• BSI CERT-Bund14 Oct 2026WID-SEC-2026-3948

  NGINX: Multiple vulnerabilities Translated from German

  Risk highCVE-2026-101025CVE-2026-15176CVE-2026-91184+8 more CVEs

[ References ]References

• my.f5.com/manage/s/article/K000162607