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
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 pathfilestatsettimes, fdfilestatsettimes, set-times, or set-times-at, crashing the host.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/rust-wasmtimeto a version that resolves this vulnerability.Fixed in 36.0.20+dfsg-1
Event History
Frequently Asked Questions
Which deployments are exposed to this denial of service?
Deployments using affected Wasmtime versions with the wasmtime-wasi component are exposed when they run guest WASI programs that can invoke the affected filesystem timestamp-setting operations. The impact is a host crash, not confidentiality or integrity loss.
What does an attacker need to trigger the crash?
An attacker needs the ability to run or supply a guest WASI program that calls path_filestat_set_times, fd_filestat_set_times, set-times, or set-times-at with atim or mtim values whose sub-second field overflows the seconds field. No privileges or user interaction are required according to the supplied vector.
Which versions should be remediated?
Upgrade to Wasmtime 36.0.16, 48.0.3, or 49.0.1 or later, as applicable to the release line in use. Affected ranges are versions before 36.0.16, versions from 37.0.0 before 48.0.3, and version 49.0.0 before 49.0.1.