CVE-2026-42533

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-42533", "assignerOrgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "state": "PUBLISHED", "assignerShortName": "f5", "dateReserved": "2026-05-05T21:19:09.517Z", "datePublished": "2026-07-15T14:33:45.810Z", "dateUpdated": "2026-11-03T22:13:24.275Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "shortName": "f5", "dateUpdated": "2026-07-15T21:20:26.156Z"}, "title": "NGINX Map directive and Regex matching vulnerability", "datePublic": "2026-07-15T14:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-122", "description": "CWE-122 Heap-based Buffer Overflow", "type": "CWE"}]}], "affected": [{"vendor": "F5", "product": "NGINX Plus", "modules": ["map directive with regex matching"], "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", "product": "NGINX Open Source", "modules": ["map directive with regex matching"], "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"}], "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.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>A vulnerability exists in NGINX Plus and NGINX Open Source when a <strong>map</strong>&nbsp;directive 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.</p>Impact:<br>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>\n\n\n<br>&nbsp;Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}]}], "references": [{"url": "https://my.f5.com/manage/s/article/K000162097", "tags": ["vendor-advisory", "patch"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 8.1, "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"version": "4.0", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subAvailabilityImpact": "NONE", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "baseSeverity": "CRITICAL", "baseScore": 9.2, "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"}}], "credits": [{"lang": "en", "value": "F5 acknowledges Ming Xuan, DKD (@pidifn), Ji'an Zhou, and Zhen Yan of AntAISecurityLab, Rafael Gacek, Sergii Negodiuk of EVO.company, Lam Jun Rong of Calif.io, Mufeed VH of Winfunc Research (winfunc.com), Vexera AI (https://vexera.ai), Tu Tran Dinh (@1w4y), Stan Shaw (cyberstan), qianshuidewajueji, zenneth (randomguy6407), Zhenpeng (Leo) Lin of depthfirst, Lukas Johannes Moeller, Melih Tolga Sahin of Vodafone T\u00fcrkiye, Ayoub Nabil Boubagrat (GitHub: @ayoubnabil), and Milan Jovic (Kljunowsky) for independently bringing this issue to our attention and following the highest standards of coordinated disclosure.", "type": "reporter"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "F5 SIRTBot v1.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-42533", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-07-29T03:55:25.631530Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-03T22:13:24.275Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-42533", "assignerOrgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "state": "PUBLISHED", "assignerShortName": "f5", "dateReserved": "2026-05-05T21:19:09.517Z", "datePublished": "2026-07-15T14:33:45.810Z", "dateUpdated": "2026-11-03T22:13:24.275Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab", "shortName": "f5", "dateUpdated": "2026-07-15T21:20:26.156Z"}, "title": "NGINX Map directive and Regex matching vulnerability", "datePublic": "2026-07-15T14:00:00.000Z", "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-122", "description": "CWE-122 Heap-based Buffer Overflow", "type": "CWE"}]}], "affected": [{"vendor": "F5", "product": "NGINX Plus", "modules": ["map directive with regex matching"], "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", "product": "NGINX Open Source", "modules": ["map directive with regex matching"], "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"}], "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.", "supportingMedia": [{"type": "text/html", "base64": false, "value": "<p>A vulnerability exists in NGINX Plus and NGINX Open Source when a <strong>map</strong>&nbsp;directive 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.</p>Impact:<br>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>\n\n\n<br>&nbsp;Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated."}]}], "references": [{"url": "https://my.f5.com/manage/s/article/K000162097", "tags": ["vendor-advisory", "patch"]}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "attackVector": "NETWORK", "attackComplexity": "HIGH", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH", "baseSeverity": "HIGH", "baseScore": 8.1, "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"}}, {"format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}], "cvssV4_0": {"version": "4.0", "attackVector": "NETWORK", "attackComplexity": "HIGH", "attackRequirements": "NONE", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "HIGH", "subConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "subIntegrityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "subAvailabilityImpact": "NONE", "Safety": "NOT_DEFINED", "Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "valueDensity": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "baseSeverity": "CRITICAL", "baseScore": 9.2, "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"}}], "credits": [{"lang": "en", "value": "F5 acknowledges Ming Xuan, DKD (@pidifn), Ji'an Zhou, and Zhen Yan of AntAISecurityLab, Rafael Gacek, Sergii Negodiuk of EVO.company, Lam Jun Rong of Calif.io, Mufeed VH of Winfunc Research (winfunc.com), Vexera AI (https://vexera.ai), Tu Tran Dinh (@1w4y), Stan Shaw (cyberstan), qianshuidewajueji, zenneth (randomguy6407), Zhenpeng (Leo) Lin of depthfirst, Lukas Johannes Moeller, Melih Tolga Sahin of Vodafone T\u00fcrkiye, Ayoub Nabil Boubagrat (GitHub: @ayoubnabil), and Milan Jovic (Kljunowsky) for independently bringing this issue to our attention and following the highest standards of coordinated disclosure.", "type": "reporter"}], "source": {"discovery": "EXTERNAL"}, "x_generator": {"engine": "F5 SIRTBot v1.0"}}, "adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-42533", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-07-29T03:55:25.631530Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-15T15:37:52.337Z"}}]}}

{"affected": [{"affectedData": [{"defaultStatus": "unknown", "modules": ["map directive with regex matching"], "product": "NGINX Plus", "vendor": "F5", "versions": [{"lessThan": "37.0.3.1", "status": "affected", "version": "37.0.0.1", "versionType": "custom"}, {"lessThan": "R36 P7", "status": "affected", "version": "R36", "versionType": "custom"}, {"lessThan": "*", "status": "affected", "version": "R33", "versionType": "custom"}]}, {"defaultStatus": "unknown", "modules": ["map directive with regex matching"], "product": "NGINX Open Source", "vendor": "F5", "versions": [{"lessThan": "1.31.3", "status": "affected", "version": "1.31.2", "versionType": "custom"}, {"lessThan": "1.30.4", "status": "affected", "version": "0.9.6", "versionType": "custom"}]}], "source": "f5sirt@f5.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:*", "matchCriteriaId": "15B7F1FD-0C49-460F-9CB8-23DA730EC4BE", "versionEndIncluding": "1.6.2", "versionStartIncluding": "1.3.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_gateway_fabric:*:*:*:*:*:*:*:*", "matchCriteriaId": "0E26414B-CC24-4618-80C5-4B96013A8920", "versionEndExcluding": "2.6.7", "versionStartIncluding": "2.0.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:*", "matchCriteriaId": "E54B5C35-49D7-43F6-B57C-4606F75192CE", "versionEndIncluding": "3.7.2", "versionStartIncluding": "3.5.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:continuous_releases:*:*:*", "matchCriteriaId": "2156F0F4-1515-45E7-8A13-F653F3796CAF", "versionEndExcluding": "5.5.3", "versionStartIncluding": "5.0.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:*:*:*:*:long-term_support:*:*:*", "matchCriteriaId": "95CF6424-294F-41A0-B28C-B35862F3D9E5", "versionEndExcluding": "2026-lts-r4", "versionStartIncluding": "2026-lts-r1", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:4.0.0:*:*:*:continuous_releases:*:*:*", "matchCriteriaId": "109F4C2E-4A5E-4B5E-B282-21AFD52AEC60", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_ingress_controller:4.0.1:*:*:*:continuous_releases:*:*:*", "matchCriteriaId": "717D820A-78A2-41EF-BB3C-5745B6D954C1", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*", "matchCriteriaId": "A1E34F4A-5F43-4048-9216-5A8AABD33F72", "versionEndExcluding": "37.0.3.1", "versionStartIncluding": "37.0.0.1", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:*:*:*:*:*:*:*:*", "matchCriteriaId": "87DE2F03-FB1E-48DC-9EEE-B3268BB4C615", "versionEndExcluding": "r36", "versionStartIncluding": "r33", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:-:*:*:*:*:*:*", "matchCriteriaId": "E7E5F940-048A-446F-9A1E-074612CEA1AC", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p1:*:*:*:*:*:*", "matchCriteriaId": "7993A0FB-BE7E-4634-BF7F-FDEE3582D3E7", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p2:*:*:*:*:*:*", "matchCriteriaId": "862EA47E-8D57-434E-9C8F-238325FB85B2", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p3:*:*:*:*:*:*", "matchCriteriaId": "7B52C01B-F719-4C72-BB83-7B70EC4BC029", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p4:*:*:*:*:*:*", "matchCriteriaId": "9F2211E4-93B9-4F1F-BA32-F5C34B879688", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p5:*:*:*:*:*:*", "matchCriteriaId": "284E9DB5-02EB-40E9-9DF3-E8F8144775ED", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:nginx_plus:r36:p6:*:*:*:*:*:*", "matchCriteriaId": "0680DC66-0B6F-4E86-B0E6-BCC235A837CE", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*", "matchCriteriaId": "021B6D53-5F4A-4A4B-AC2F-CFBEC338F69F", "versionEndIncluding": "4.16.0", "versionStartIncluding": "4.11.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*", "matchCriteriaId": "2DB79E6C-08B0-4341-BCBE-B8070DDAA7AF", "versionEndIncluding": "5.8.0", "versionStartIncluding": "5.2.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:f5:waf:*:*:*:*:*:nginx:*:*", "matchCriteriaId": "4EA246F7-5222-4403-BFEA-160195FD39B2", "versionEndExcluding": "5.13.4", "versionStartIncluding": "5.9.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "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."}], "id": "CVE-2026-42533", "lastModified": "2026-11-03T23:17:43.553", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 2.2, "impactScore": 5.9, "source": "f5sirt@f5.com", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 9.2, "baseSeverity": "CRITICAL", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "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/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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "f5sirt@f5.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-42533", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-07-29T03:55:25.631530Z", "version": "2.0.3"}}]}, "published": "2026-07-15T15:16:33.480", "references": [{"source": "f5sirt@f5.com", "tags": ["Vendor Advisory"], "url": "https://my.f5.com/manage/s/article/K000162097"}], "sourceIdentifier": "f5sirt@f5.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "f5sirt@f5.com", "type": "Secondary"}]}

{"bugzilla": {"description": "nginx: NGINX: Arbitrary code execution via crafted HTTP requests", "id": "2500967", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2500967"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H", "status": "draft"}, "cwe": "CWE-131", "details": ["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.\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\u00a0Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.", "A flaw was found in NGINX. An unauthenticated attacker can exploit this vulnerability by sending specially crafted HTTP requests when the `map` directive uses regular expression (regex) matching and references regex capture variables before referencing the map output variable. This can lead to a heap buffer overflow, which may allow for arbitrary code execution on systems where Address Space Layout Randomization (ASLR) is disabled or bypassed. Additionally, this flaw can cause a denial-of-service (DoS) due to the NGINX worker process restarting."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. Red Hat recommends updating nginx to the latest version when a fix is available."}, "name": "CVE-2026-42533", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "impact": "moderate", "package_name": "nginx", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "impact": "moderate", "package_name": "nginx:1.24/nginx", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "impact": "moderate", "package_name": "nginx", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "impact": "moderate", "package_name": "nginx:1.24/nginx", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "impact": "moderate", "package_name": "nginx:1.26/nginx", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "impact": "important", "package_name": "nginx", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "impact": "important", "package_name": "php", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:insights_proxy:1", "fix_state": "Affected", "impact": "moderate", "package_name": "insights-proxy/insights-proxy-container-rhel9", "product_name": "Red Hat Lightspeed proxy 1"}], "public_date": "2026-07-15T14:33:45Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-42533\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-42533\nhttps://my.f5.com/manage/s/article/K000162097"], "statement": "An Important vulnerability in NGINX allows a remote, unauthenticated attacker to trigger a heap buffer overflow, leading to a denial of service. This occurs when the `map` directive uses regex matching and references regex capture variables before the map output variable. While arbitrary code execution is a theoretical risk, it is significantly reduced on Red Hat systems where Address Space Layout Randomization (ASLR) is enabled by default.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.31.2,1.31.3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0.9.6,1.30.4)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "NGINX Open Source", "source": "cna", "vendor": "F5"}, "product": "nginx_open_source", "vendor": "f5"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[37.0.0.1,37.0.3.1)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[R36,R36 P7)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[R33,*]"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "NGINX Plus", "source": "cna", "vendor": "F5"}, "product": "nginx_plus", "vendor": "f5"}], "created": "2026-07-15T23:15:15.710390+00:00", "updated": "2026-11-01T14:30:07.100355+00:00", "vendors": ["f5", "f5$PRODUCT$nginx_open_source", "f5$PRODUCT$nginx_plus"], "weaknesses": ["CWE-122", "CWE-131"]}