{"id":"CVE-2026-115386","title":"Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 Memory Disclosure via fd_readdir","summary":"Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an information disclosure vulnerability in the WASIp1 fd_readdir implementation that copies uninitialized struct padding into guest memory. Guests with a pr…","severity":"low","cvss":2.6,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N","cvssSource":"cna","cwe":["CWE-908"],"vendor":"bytecodealliance","product":"wasmtime","affected":["wasmtime < 36.0.17","wasmtime >= 37.0.0 < 48.0.4","wasmtime >= 49.0.0 < 49.0.2"],"published":"2026-10-22","updated":"2026-10-22","sourceUpdated":"2026-10-22T19:13:52.931Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-115386","references":[{"url":"https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-96f6-r43r-8c24","label":"GitHub Security Advisory (GHSA-96f6-r43r-8c24)"},{"url":"https://www.vulncheck.com/advisories/wasmtime-before-36.0.17-37.0.0-before-48.0.4-and-49.0.0-before-49.0.2-memory-disclosure-via-fd-readdir","label":"VulnCheck Advisory: Wasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 Memory Disclosure via fd_readdir"}],"tags":["cve.org"],"ingestedAt":"2026-10-22T22:00:50.405Z","slug":"CVE-2026-115386","body":"## Overview\n\nWasmtime before 36.0.17, 37.0.0 before 48.0.4, and 49.0.0 before 49.0.2 contains an information disclosure vulnerability in the WASIp1 fd_readdir implementation that copies uninitialized struct padding into guest memory. Guests with a preopened directory can list entries to receive three bytes of leftover host stack or heap memory per directory entry.\n\n## Affected\n\n- `wasmtime < 36.0.17`\n- `wasmtime >= 37.0.0 < 48.0.4`\n- `wasmtime >= 49.0.0 < 49.0.2`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":14,"depthScoreParts":{"impact":14.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}