CVE-2026-54786

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{"affected": [{"affectedData": [{"product": "wasmtime", "vendor": "bytecodealliance", "versions": [{"status": "affected", "version": "< 24.0.10"}, {"status": "affected", "version": ">= 25.0.0, < 36.0.11"}, {"status": "affected", "version": ">= 37.0.0, < 44.0.3"}, {"status": "affected", "version": ">= 45.0.0, < 45.0.2"}]}], "source": "security-advisories@github.com"}], "configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*", "matchCriteriaId": "630EB6DB-BA29-49A9-9FA7-E3312EEF73D5", "versionEndExcluding": "24.0.10", "vulnerable": true}, {"criteria": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*", "matchCriteriaId": "E5F60B40-01E2-448C-BDF1-A17D2207A5C9", "versionEndExcluding": "36.0.11", "versionStartIncluding": "25.0.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*", "matchCriteriaId": "DF13A6A0-0A9E-4158-8A89-AC89A68E9E06", "versionEndExcluding": "44.0.3", "versionStartIncluding": "37.0.0", "vulnerable": true}, {"criteria": "cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*", "matchCriteriaId": "116B898A-D85E-4775-9528-A9970DD13FFF", "versionEndExcluding": "45.0.2", "versionStartIncluding": "45.0.0", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Wasmtime is a runtime for WebAssembly. All versions prior to 24.0.10; versions 25.0.0 through those before 36.0.11; versions 37.0.0 through those before 44.0.3; and versions 45.0.0 and 45.0.1 contain a native implementation of WASIp1 which suffers from a leak in the fd_renumber function where the file descriptor being renumbered to is not properly closed. Wasmtime's implementation erroneously only updated the table of descriptors for WASIp1 and didn't update the underlying table of descriptors used by the host. This behavior means that while fd_renumber works correctly from a guest's perspective it ends up leaking resources in the host that aren't cleaned up until the corresponding Store is destroyed. In a loop, guests can use fd_renumber to cause hosts to exhaust both resources and file descriptors. This bug only affects the native implementation of WASIp1, meaning that only runtimes which load core wasm modules and expose fd_renumber are affected. Runtimes are additionally only affected if they expose the ability to acquire a file descriptor, such as opening a file. For runtimes that deny access to files they are unaffected. This issue has been fixed in versions 24.0.10, 36.0.11, 44.0.3, and 45.0.2."}, {"lang": "es", "value": "Wasmtime es un entorno de ejecuci\u00f3n para WebAssembly. Todas las versiones anteriores a la 24.0.10; las versiones 25.0.0 hasta las anteriores a la 36.0.11; las versiones 37.0.0 hasta las anteriores a la 44.0.3; y las versiones 45.0.0 y 45.0.1 contienen una implementaci\u00f3n nativa de WASIp1 que sufre de una fuga en la funci\u00f3n fd_renumber donde el descriptor de archivo al que se le cambia el n\u00famero no se cierra correctamente. La implementaci\u00f3n de Wasmtime err\u00f3neamente solo actualiz\u00f3 la tabla de descriptores para WASIp1 y no actualiz\u00f3 la tabla subyacente de descriptores utilizada por el host. Este comportamiento significa que, si bien fd_renumber funciona correctamente desde la perspectiva de un invitado, termina fugando recursos en el host que no se limpian hasta que se destruye el Store correspondiente. En un bucle, los invitados pueden usar fd_renumber para hacer que los hosts agoten tanto los recursos como los descriptores de archivo. Este error solo afecta la implementaci\u00f3n nativa de WASIp1, lo que significa que solo los entornos de ejecuci\u00f3n que cargan m\u00f3dulos wasm centrales y exponen fd_renumber se ven afectados. Los entornos de ejecuci\u00f3n tambi\u00e9n solo se ven afectados si exponen la capacidad de adquirir un descriptor de archivo, como abrir un archivo. Para los entornos de ejecuci\u00f3n que deniegan el acceso a archivos, no se ven afectados. Este problema ha sido solucionado en las versiones 24.0.10, 36.0.11, 44.0.3 y 45.0.2."}], "id": "CVE-2026-54786", "lastModified": "2026-10-25T16:10:00.147", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "LOW", "baseScore": 5.0, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:L", "version": "3.1"}, "exploitabilityScore": 3.1, "impactScore": 1.4, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 2.3, "baseSeverity": "LOW", "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": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/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": "LOW", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-54786", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-07-02T12:44:47.360688Z", "version": "2.0.3"}}]}, "published": "2026-07-01T21:17:03.690", "references": [{"source": "security-advisories@github.com", "tags": ["Vendor Advisory"], "url": "https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3p27-qvp9-27qf"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-772"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "Wasmtime: Wasmtime: Leak in WASIp1 `fd_renumber` implementation", "id": "2496195", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2496195"}, "csaw": false, "cwe": "CWE-772", "details": ["Wasmtime is a runtime for WebAssembly. All versions prior to 24.0.10; versions 25.0.0 through those before 36.0.11; versions 37.0.0 through those before 44.0.3; and versions 45.0.0 and 45.0.1 contain a native implementation of WASIp1 which suffers from a leak in the fd_renumber function where the file descriptor being renumbered to is not properly closed. Wasmtime's implementation erroneously only updated the table of descriptors for WASIp1 and didn't update the underlying table of descriptors used by the host. This behavior means that while fd_renumber works correctly from a guest's perspective it ends up leaking resources in the host that aren't cleaned up until the corresponding Store is destroyed. In a loop, guests can use fd_renumber to cause hosts to exhaust both resources and file descriptors. This bug only affects the native implementation of WASIp1, meaning that only runtimes which load core wasm modules and expose fd_renumber are affected. Runtimes are additionally only affected if they expose the ability to acquire a file descriptor, such as opening a file. For runtimes that deny access to files they are unaffected. This issue has been fixed in versions 24.0.10, 36.0.11, 44.0.3, and 45.0.2.", "A flaw was found in Wasmtime, a runtime for WebAssembly. Its native implementation of WASIp1, a system interface for WebAssembly, contains a resource leak in the fd_renumber function. A malicious guest program can repeatedly call this function, causing the host system to exhaust its file descriptors (system resources used to access files or other input/output sources) and other resources. This can lead to a Denial of Service (DoS), making the system unavailable."], "mitigation": {"lang": "en:us", "value": "To mitigate this issue, configure Wasmtime environments to deny guest programs the ability to acquire file descriptors, such as preventing file system access. This restriction limits the attack surface by preventing the `fd_renumber` function from leaking host resources. Consult product-specific documentation for instructions on configuring Wasmtime security policies to restrict file access. If the Wasmtime service is reloaded or restarted, ensure the configuration changes persist."}, "name": "CVE-2026-54786", "package_state": [{"cpe": "cpe:/a:redhat:connectivity_link:1", "fix_state": "Fix deferred", "package_name": "rhcl-1/wasm-shim-rhel9", "product_name": "Red Hat Connectivity Link 1"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "virt-firmware-rs", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Affected", "package_name": "rust", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-07-01T20:12:35Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-54786\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-54786\nhttps://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3p27-qvp9-27qf"], "statement": "This flaw is rated as Low impact. Wasmtime's WASIp1 implementation can leak file descriptors when renumbering, allowing a malicious guest program to exhaust host resources and cause a Denial of Service. This issue primarily affects Red Hat products that utilize Wasmtime with WASIp1 enabled and allow guest programs to acquire file descriptors.", "threat_severity": "Low"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,24.0.10)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[25.0.0,36.0.11)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[37.0.0,44.0.3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[45.0.0,45.0.2)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "wasmtime", "source": "cna", "vendor": "bytecodealliance"}, "product": "wasmtime", "vendor": "bytecodealliance"}], "created": "2026-07-02T03:15:16.074201+00:00", "updated": "2026-08-01T22:45:03.813910+00:00", "vendors": ["bytecodealliance", "bytecodealliance$PRODUCT$wasmtime"]}