Sandbox escape in Wasmtime WASI via symlinks with trailing slashes
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- Passive
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · Low
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
Wasmtime before 24.0.13, from 25.0.0 before 36.0.14, from 37.0.0 before 46.0.3, and from 47.0.0 before 47.0.4 contains a filesystem sandbox escape in wasmtime-wasi. Its cap-std dependency mishandles symlinks with trailing slashes on macOS and Linux kernels lacking openat2 (CWE-61). A guest with write access to any sandboxed directory can read and write any host-accessible file, and a read-only guest can read host files through preexisting symlinks.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
Description from the CNA
Wasmtime before 24.0.13, 25.0.0 before 36.0.14, 37.0.0 before 46.0.3, and 47.0.0 before 47.0.4 allows a filesystem sandbox escape in wasmtime-wasi because its cap-std dependency mishandles symlinks with trailing slashes on macOS and Linux kernels lacking openat2. A guest with write access to any sandboxed directory can read and write any host-accessible file, and read-only guests may read host files via preexisting symlinks.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| bytecodealliance | wasmtime | before 24.0.13; 25.0.0 to before 36.0.14; 37.0.0 to before 46.0.3; 47.0.0 to before 47.0.4 | 24.0.13, 36.0.14, 46.0.3, 47.0.4 | Patch available | CNA |
- wasmtime Vendorbytecodealliance Affected before 24.0.13; 25.0.0 to before 36.0.14; 37.0.0 to before 46.0.3; 47.0.0 to before 47.0.4 Fixed in 24.0.13, 36.0.14, 46.0.3, 47.0.4 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:* | — | — | bytecodealliance |
- cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:*:*:* Versions — — ·bytecodealliance
Remediation
Update Wasmtime to version 24.0.13, 36.0.14, 46.0.3, or 47.0.4, matching the release line in use.
Written with Claude Haiku 5.5 from the sources below · 2026-10-29
- Fix · CNA wasmtime (bytecodealliance) Fixed in 24.0.13, 36.0.14, 46.0.3, 47.0.4
Timeline
- 2026-10-22 Threatist record created from CVE-2026-115392
- 2026-10-22 Alias added: GHSA-gxhv-gf3j-vwqc
- 2026-10-23 Priority changed: MEDIUM → LOW
- 2026-10-29 CISA SSVC decision points changed
- 2026-10-29 Priority changed: LOW → MEDIUM
References
More bytecodealliance vulnerabilities
- TI-2026-85541 WAMR fast interpreter loader heap overflow via constant deduplication mismatch CVSS 4.0HIGH 8.8
- TI-2024-16741 An issue in bytecodealliance wasm-micro-runtime before v.b3f728c and fixed in commit… CVSS 3.1HIGH 8.8
- TI-2024-22658 An out-of-bound memory read vulnerability was discovered in Bytecode Alliance… CVSS 3.1HIGH 7.5
- TI-2024-18300 wasm-micro-runtime (aka WebAssembly Micro Runtime or WAMR) 06df58f is vulnerable to NULL… CVSS 3.1HIGH 7.5
- TI-2023-26034 An heap overflow vulnerability was discovered in Bytecode alliance wasm-micro-runtime… CVSS 3.1HIGH 7.5
- TI-2025-33969 WebAssembly Micro Runtime's `--addr-pool` option allows all IPv4 addresses when subnet mask is not specified CVSS 4.0MEDIUM 6.9
Sources
- CVE-2026-115392 · CVE Program
- CVE-2026-115392 · NVD
- FIRST EPSS
- GHSA-gxhv-gf3j-vwqc · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences