Wasmtime-wasi
Affects wasmtime-wasiSource GCVE Database
Not known to be exploited · CVSS 8.8 High · fixed in 49.0.3 : patch wasmtime-wasi soon.
Data as of 28 Oct 2026, 22:14 UTC
- Affects
- Wasmtime before 36.0.18
- Patch
- Available – fixed in 49.0.3, 48.0.6, 36.0.18
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:LExploitation evidence
Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade bytecodealliance/wasmtime-wasi to 49.0.3, 48.0.6 or 36.0.18.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
crates.iobytecodealliance/wasmtime-wasipkg:cargo/bytecodealliance/wasmtime-wasiOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
The vulnerability affects specific Wasmtime versions before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3. Users should upgrade to versions 36.0.18 or later, 48.0.6 or later, and 49.0.3 or later respectively to mitigate this issue. No vendor advisory or patch links were provided, so confirm patch availability from official Wasmtime sources before applying updates.
Description
A vulnerability in wasmtime-wasi in Wasmtime versions before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 causes a trailing slash to be re-appended to rename source paths. This behavior leads to the renameat system call on macOS and FreeBSD hosts following directory symbolic links. Consequently, a guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox, enabling unauthorized read or write access to those directories.
References
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m9f7-9w4p-gv38 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-118688 (opens in a new tab)
- vulncheck.com/advisories/wasmtime-before-36.0.18-37.0.0-before-48.0.6-and-49.0.0-before-49.0.3-sandbox-escape-via-symlink-rename (opens in a new tab)