CVE-2026-1979

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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."}, {"lang": "es", "value": "Se ha encontrado una vulnerabilidad en mruby hasta la versi\u00f3n 3.4.0. Esto afecta a la funci\u00f3n mrb_vm_exec del archivo src/vm.c del componente Optimizaci\u00f3n JMPNOT-a-JMPIF. La ejecuci\u00f3n de una manipulaci\u00f3n puede conducir a un uso despu\u00e9s de liberar. El ataque debe lanzarse localmente. El exploit ha sido publicado y puede ser utilizado. Este parche se llama e50f15c1c6e131fa7934355eb02b8173b13df415. Es aconsejable implementar un parche para corregir este problema."}], "id": "CVE-2026-1979", "lastModified": "2026-06-17T10:16:49.260", "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": "Secondary"}, {"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 1.9, "baseSeverity": "LOW", "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"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-1979", "options": [{"exploitation": "poc"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-02-06T20:26:13.479778Z", "version": "2.0.3"}}]}, "published": "2026-02-06T05:16:12.667", "references": [{"source": "cna@vuldb.com", "tags": ["Product"], "url": "https://github.com/mruby/mruby/"}, {"source": "cna@vuldb.com", "tags": ["Exploit", "Issue Tracking"], "url": "https://github.com/mruby/mruby/issues/6701"}, {"source": "cna@vuldb.com", "tags": ["Exploit", "Issue Tracking"], "url": "https://github.com/mruby/mruby/issues/6701#issue-3802609843"}, {"source": "cna@vuldb.com", "tags": ["Patch"], "url": "https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415"}, {"source": "cna@vuldb.com", "tags": ["Permissions Required", "VDB Entry"], "url": "https://vuldb.com/?ctiid.344501"}, {"source": "cna@vuldb.com", "tags": ["Third Party Advisory", "VDB Entry"], "url": "https://vuldb.com/?id.344501"}, {"source": "cna@vuldb.com", "tags": ["Third Party Advisory", "VDB Entry"], "url": "https://vuldb.com/?submit.743377"}], "sourceIdentifier": "cna@vuldb.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-119"}, {"lang": "en", "value": "CWE-416"}], "source": "cna@vuldb.com", "type": "Secondary"}]}

{}

{"analysis": {"en": {"generated_at": "2026-04-18T13:39:53.800750+00:00", "value": {"mitigation_remediation": ["Apply the patch identified by commit e50f15c1c6e131fa7934355eb02b8173b13df415 or upgrade to a later mruby release that includes this fix.", "Recompile mruby with the advised patch to ensure the optimization function no longer dereferences freed memory.", "Limit local access to untrusted code execution sites or run mruby in a sandboxed environment to minimize exposure from local attackers."], "summary": {"action": "Apply Patch", "impact": "Use\u2011after\u2011free potentially causing memory corruption on local execution"}, "threat_synthesis": {"affected_systems": "mruby versions up to 3.4.0 are affected. The bug resides in the core vm.c component and has been publicly reported with a fix committed at e50f15c1c6e131fa7934355eb02b8173b13df415. Any installation of mruby 3.4.0 or earlier that has not applied this patch is vulnerable.", "description_and_impact": "The flaw is in the JMPNOT-to-JMPIF Optimization function mrb_vm_exec and allows a use\u2011after\u2011free condition when specific code manipulations are executed. Attacking code can corrupt memory after the freed resource is referenced, which may result in unintended behavior or compromise program integrity. The vulnerability is limited to local execution and does not expose remote code execution directly.", "risk_and_exploitability": "The CVSS score of 4.8 reflects a moderate risk. EPSS indicates a low exploitation probability (<1%). The vulnerability is not listed in the CISA KEV catalog. The exploit is local, requiring the attacker to run code on the host, and currently no remote exploitation vectors are documented. The published exploit demonstrates that a local attacker can trigger the use\u2011after\u2011free, potentially leading to memory corruption."}}}}, "created": "2026-02-06T12:04:52.118483+00:00", "updated": "2026-04-18T13:45:45.675404+00:00", "vendors": ["mruby", "mruby$PRODUCT$mruby"]}