{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-1979", "assignerOrgId": "1af790b2-7ee1-4545-860a-a788eba489b5", "state": "PUBLISHED", "assignerShortName": "VulDB", "dateReserved": "2026-02-05T13:44:19.662Z", "datePublished": "2026-02-06T04:32:09.200Z", "dateUpdated": "2026-02-06T04:32:09.200Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "1af790b2-7ee1-4545-860a-a788eba489b5", "shortName": "VulDB", "dateUpdated": "2026-02-06T04:32:09.200Z"}, "title": "mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free", "problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-416", "lang": "en", "description": "Use After Free"}]}, {"descriptions": [{"type": "CWE", "cweId": "CWE-119", "lang": "en", "description": "Memory Corruption"}]}], "affected": [{"vendor": "n/a", "product": "mruby", "versions": [{"version": "3.0", "status": "affected"}, {"version": "3.1", "status": "affected"}, {"version": "3.2", "status": "affected"}, {"version": "3.3", "status": "affected"}, {"version": "3.4.0", "status": "affected"}], "modules": ["JMPNOT-to-JMPIF Optimization"]}], "descriptions": [{"lang": "en", "value": "A flaw has been found in mruby up to 3.4.0. This affects the function mrb_vm_exec of the file src/vm.c of the component JMPNOT-to-JMPIF Optimization. Executing a manipulation can lead to use after free. The attack needs to be launched locally. The exploit has been published and may be used. This patch is called e50f15c1c6e131fa7934355eb02b8173b13df415. It is advisable to implement a patch to correct this issue."}], "metrics": [{"cvssV4_0": {"version": "4.0", "baseScore": 4.8, "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P", "baseSeverity": "MEDIUM"}}, {"cvssV3_1": {"version": "3.1", "baseScore": 5.3, "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C", "baseSeverity": "MEDIUM"}}, {"cvssV3_0": {"version": "3.0", "baseScore": 5.3, "vectorString": "CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C", "baseSeverity": "MEDIUM"}}, {"cvssV2_0": {"version": "2.0", "baseScore": 4.3, "vectorString": "AV:L/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:OF/RC:C"}}], "timeline": [{"time": "2026-02-05T00:00:00.000Z", "lang": "en", "value": "Advisory disclosed"}, {"time": "2026-02-05T01:00:00.000Z", "lang": "en", "value": "VulDB entry created"}, {"time": "2026-02-05T14:49:24.000Z", "lang": "en", "value": "VulDB entry last update"}], "credits": [{"lang": "en", "value": "Oneafter (VulDB User)", "type": "reporter"}], "references": [{"url": "https://vuldb.com/?id.344501", "name": "VDB-344501 | mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free", "tags": ["vdb-entry", "technical-description"]}, {"url": "https://vuldb.com/?ctiid.344501", "name": "VDB-344501 | CTI Indicators (IOB, IOC, IOA)", "tags": ["signature", "permissions-required"]}, {"url": "https://vuldb.com/?submit.743377", "name": "Submit #743377 | mruby cda2567 Use After Free", "tags": ["third-party-advisory"]}, {"url": "https://github.com/mruby/mruby/issues/6701", "tags": ["issue-tracking"]}, {"url": "https://github.com/mruby/mruby/issues/6701#issue-3802609843", "tags": ["exploit", "issue-tracking"]}, {"url": "https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415", "tags": ["patch"]}, {"url": "https://github.com/mruby/mruby/", "tags": ["product"]}], "tags": ["x_open-source"]}}}

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{"cveTags": [], "descriptions": [{"lang": "en", "value": "A flaw has been found in mruby up to 3.4.0. This affects the function mrb_vm_exec of the file src/vm.c of the component JMPNOT-to-JMPIF Optimization. Executing a manipulation can lead to use after free. The attack needs to be launched locally. The exploit has been published and may be used. This patch is called e50f15c1c6e131fa7934355eb02b8173b13df415. It is advisable to implement a patch to correct this issue."}], "id": "CVE-2026-1979", "lastModified": "2026-02-06T05:16:12.667", "metrics": {"cvssMetricV2": [{"acInsufInfo": false, "baseSeverity": "MEDIUM", "cvssData": {"accessComplexity": "LOW", "accessVector": "LOCAL", "authentication": "SINGLE", "availabilityImpact": "PARTIAL", "baseScore": 4.3, "confidentialityImpact": "PARTIAL", "integrityImpact": "PARTIAL", "vectorString": "AV:L/AC:L/Au:S/C:P/I:P/A:P", "version": "2.0"}, "exploitabilityScore": 3.1, "impactScore": 6.4, "obtainAllPrivilege": false, "obtainOtherPrivilege": false, "obtainUserPrivilege": false, "source": "cna@vuldb.com", "type": "Secondary", "userInteractionRequired": false}], "cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "LOW", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.4, "source": "cna@vuldb.com", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 4.8, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "PROOF_OF_CONCEPT", "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": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/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": "LOW", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "cna@vuldb.com", "type": "Secondary"}]}, "published": "2026-02-06T05:16:12.667", "references": [{"source": "cna@vuldb.com", "url": "https://github.com/mruby/mruby/"}, {"source": "cna@vuldb.com", "url": "https://github.com/mruby/mruby/issues/6701"}, {"source": "cna@vuldb.com", "url": "https://github.com/mruby/mruby/issues/6701#issue-3802609843"}, {"source": "cna@vuldb.com", "url": "https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415"}, {"source": "cna@vuldb.com", "url": "https://vuldb.com/?ctiid.344501"}, {"source": "cna@vuldb.com", "url": "https://vuldb.com/?id.344501"}, {"source": "cna@vuldb.com", "url": "https://vuldb.com/?submit.743377"}], "sourceIdentifier": "cna@vuldb.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-119"}, {"lang": "en", "value": "CWE-416"}], "source": "cna@vuldb.com", "type": "Primary"}]}

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