{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-93479","assignerOrgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","state":"PUBLISHED","assignerShortName":"f5","dateReserved":"2026-09-30T21:56:14.601Z","datePublished":"2026-10-14T14:40:27.107Z","dateUpdated":"2026-10-15T03:56:59.923Z"},"containers":{"cna":{"affected":[{"defaultStatus":"unknown","modules":["The map directive with regex matching"],"product":"NGINX Plus","vendor":"F5","versions":[{"lessThan":"37.1.0.1","status":"affected","version":"37.1.0","versionType":"custom"},{"lessThan":"37.0.5.1","status":"affected","version":"37.0.0","versionType":"custom"},{"lessThan":"*","status":"affected","version":"R36","versionType":"custom"},{"lessThan":"*","status":"affected","version":"R35","versionType":"custom"},{"lessThan":"*","status":"affected","version":"R34","versionType":"custom"},{"lessThan":"*","status":"affected","version":"R33","versionType":"custom"}]},{"defaultStatus":"unaffected","modules":["The map directive with regex matching"],"product":"NGINX Open Source","vendor":"F5","versions":[{"lessThan":"1.31.7","status":"affected","version":"1.31.2","versionType":"custom"},{"lessThan":"1.30.6","status":"affected","version":"1.30.0","versionType":"custom"}]}],"credits":[{"lang":"en","type":"reporter","value":"F5 acknowledges \"Matt Suiche\" of \"Tolmo, Inc.\"  and \"Mateusz Gierblinski \" for bringing this issue to our attention and following the highest standards of coordinated disclosure."}],"datePublic":"2023-01-01T00:00:00.000Z","descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<span style=\"background-color: rgb(255, 255, 255);\">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.</span><br><br>Impact:&nbsp;<br><span style=\"background-color: rgb(255, 255, 255);\">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.<br><br><span style=\"background-color: rgb(255, 255, 255);\">Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.</span></span><br>"}],"value":"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.\n\nImpact: \nThis 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.\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}],"impacts":[{"capecId":"CAPEC-100","descriptions":[{"lang":"en","value":"CAPEC-100 Overflow Buffers"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":8.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]},{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"HIGH","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":9.2,"baseSeverity":"CRITICAL","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-122","description":"CWE-122 Heap-based Buffer Overflow","lang":"en","type":"CWE"}]}],"providerMetadata":{"orgId":"9dacffd4-cb11-413f-8451-fbbfd4ddc0ab","shortName":"f5","dateUpdated":"2026-10-14T14:40:27.107Z"},"references":[{"tags":["vendor-advisory"],"url":"https://my.f5.com/manage/s/article/K000162607"}],"source":{"discovery":"EXTERNAL"},"title":"NGINX map directive and regex matching vulnerability","workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<span style=\"background-color: rgb(255, 255, 255);\">To mitigate this vulnerability, do not use unnamed captures. Use named captures instead and limit their usage to the block with the regex match.</span><br>"}],"value":"To mitigate this vulnerability, do not use unnamed captures. Use named captures instead and limit their usage to the block with the regex match."}],"x_generator":{"engine":"F5 SIRTBot v1.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-14T00:00:00+00:00","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-93479"}}}],"providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-10-15T03:56:59.923Z"}}]}}