CVE-2026-42533

{"id": "CVE-2026-42533", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-42533", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "version": "2.0.3", "timestamp": "2026-07-15T00:00:00+00:00"}}], "cvssMetricV31": [{"type": "Secondary", "source": "f5sirt@f5.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 8.1, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 5.9, "exploitabilityScore": 2.2}], "cvssMetricV40": [{"type": "Secondary", "source": "f5sirt@f5.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9.2, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "f5sirt@f5.com", "affectedData": [{"vendor": "F5", "modules": ["map directive with regex matching"], "product": "NGINX Plus", "versions": [{"status": "affected", "version": "37.0.0.1", "lessThan": "37.0.3.1", "versionType": "custom"}, {"status": "affected", "version": "R36", "lessThan": "R36 P7", "versionType": "custom"}, {"status": "affected", "version": "R33", "lessThan": "*", "versionType": "custom"}], "defaultStatus": "unknown"}, {"vendor": "F5", "modules": ["map directive with regex matching"], "product": "NGINX Open Source", "versions": [{"status": "affected", "version": "1.31.2", "lessThan": "1.31.3", "versionType": "custom"}, {"status": "affected", "version": "0.9.6", "lessThan": "1.30.4", "versionType": "custom"}], "defaultStatus": "unknown"}]}], "published": "2026-07-15T15:16:33.480", "references": [{"url": "https://my.f5.com/manage/s/article/K000162097", "tags": ["Vendor Advisory"], "source": "f5sirt@f5.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "f5sirt@f5.com", "description": [{"lang": "en", "value": "CWE-122"}]}], "descriptions": [{"lang": "en", "value": "A vulnerability exists in NGINX Plus and NGINX Open Source when a map\u00a0directive uses regex matching and a string expression 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\n\n\n\n\u00a0Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}], "lastModified": "2026-08-10T15:28:01.940", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "15B7F1FD-0C49-460F-9CB8-23DA730EC4BE", "versionEndIncluding": "1.6.2", "versionStartIncluding": "1.3.0"}, {"criteria": "cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0E26414B-CC24-4618-80C5-4B96013A8920", "versionEndExcluding": "2.6.7", "versionStartIncluding": "2.0.0"}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:*", "vulnerable": true, "matchCriteriaId": "E54B5C35-49D7-43F6-B57C-4606F75192CE", "versionEndIncluding": "3.7.2", "versionStartIncluding": "3.5.0"}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:*", "vulnerable": true, "matchCriteriaId": "2156F0F4-1515-45E7-8A13-F653F3796CAF", "versionEndExcluding": "5.5.3", "versionStartIncluding": "5.0.0"}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:long-term_support:*:*:*", "vulnerable": true, "matchCriteriaId": "95CF6424-294F-41A0-B28C-B35862F3D9E5", "versionEndExcluding": "2026-lts-r4", "versionStartIncluding": "2026-lts-r1"}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:4.0.0:*:*:*:continuous_releases:*:*:*", "vulnerable": true, "matchCriteriaId": "109F4C2E-4A5E-4B5E-B282-21AFD52AEC60"}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:4.0.1:*:*:*:continuous_releases:*:*:*", "vulnerable": true, "matchCriteriaId": "717D820A-78A2-41EF-BB3C-5745B6D954C1"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "A1E34F4A-5F43-4048-9216-5A8AABD33F72", "versionEndExcluding": "37.0.3.1", "versionStartIncluding": "37.0.0.1"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "87DE2F03-FB1E-48DC-9EEE-B3268BB4C615", "versionEndExcluding": "r36", "versionStartIncluding": "r33"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:-:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E7E5F940-048A-446F-9A1E-074612CEA1AC"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7993A0FB-BE7E-4634-BF7F-FDEE3582D3E7"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "862EA47E-8D57-434E-9C8F-238325FB85B2"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7B52C01B-F719-4C72-BB83-7B70EC4BC029"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "9F2211E4-93B9-4F1F-BA32-F5C34B879688"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "284E9DB5-02EB-40E9-9DF3-E8F8144775ED"}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p6:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0680DC66-0B6F-4E86-B0E6-BCC235A837CE"}, {"criteria": "cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*", "vulnerable": true, "matchCriteriaId": "021B6D53-5F4A-4A4B-AC2F-CFBEC338F69F", "versionEndIncluding": "4.16.0", "versionStartIncluding": "4.11.0"}, {"criteria": "cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*", "vulnerable": true, "matchCriteriaId": "2DB79E6C-08B0-4341-BCBE-B8070DDAA7AF", "versionEndIncluding": "5.8.0", "versionStartIncluding": "5.2.0"}, {"criteria": "cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*", "vulnerable": true, "matchCriteriaId": "4EA246F7-5222-4403-BFEA-160195FD39B2", "versionEndExcluding": "5.13.4", "versionStartIncluding": "5.9.0"}], "operator": "OR"}]}], "sourceIdentifier": "f5sirt@f5.com"}