Vulnerability in Bytecodealliance Wasmtime
CVE-2026-115386
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 preopened directory can list entries to receive three bytes of leftover host stack or heap memory per directory entry.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 2.6 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-96f6-r43r-8c24 (vendor-advisory)
- www.vulncheck.com/advisories/wasmtime-before-36.0.17-37.0.0-before-48.0.4-and-4… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-115386?
- CVE-2026-115386 is a low-severity vulnerability in Bytecodealliance Wasmtime, classified under Use of Uninitialized Resource. CVSS score: 2.6/10. Published 2026-10-22.
- How severe is CVE-2026-115386?
- Low severity. CVSS v3 base score is 2.6 out of 10.