What’s Vulnerable › Vulnerabilities

CVE-2026-115387: Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Host Panic via WASI Filesystem Timestamp Overflow

• Severity: medium (CVSS 6.2 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-22 · updated 2026-10-22
• Weakness: CWE-190

Description

Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 contains a denial of service vulnerability in wasmtime-wasi that allows guest WASI programs to panic the host via overflowing filesystem timestamps. Attackers can pass atim or mtim values whose sub-second field overflows the seconds field to path_filestat_set_times, fd_filestat_set_times, set-times, or set-times-at, crashing the host.

Affected products

• bytecodealliance wasmtime: before 36.0.16; from 37.0.0 before 48.0.3; from 49.0.0 before 49.0.1 — fixed in 36.0.16, 48.0.3, 49.0.1

How to fix

Upgrade to a fixed version: bytecodealliance wasmtime 36.0.16, 48.0.3, 49.0.1. Check the vendor advisory for mitigations.

References

• https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-j2g9-4prp-pf6h
• https://www.vulncheck.com/advisories/wasmtime-before-36.0.16-37.0.0-before-48.0.3-and-49.0.0-before-49.0.1-host-panic-via-wasi-filesystem-timestamp-overflow

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