CVE-2026-118688
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
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
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
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
- Record
CVE-2026-118688- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L - CVSS 3.1
- 7.9 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L - Weakness
- CWE-61
- Updated
- 2026-11-04
EUVDEUVD-2026-112393
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
- Record
EUVD-2026-112393- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L - Updated
- 2026-11-04
GitHub AdvisoriesGHSA-63fr-xrxj-8wrx
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re...
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
- Record
GHSA-63fr-xrxj-8wrx- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.9 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L - Weakness
- CWE-61
- Updated
- 2026-11-02
NVD
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
- Record
CVE-2026-118688- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.9 High
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:L - Weakness
- CWE-61
- Updated
- 2026-11-04
OSV
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
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
- Record
CVE-2026-118688- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L - Weakness
- CWE-61
- Updated
- 2026-11-05
OSVDEBIAN-CVE-2026-118688
wasmtime-wasi in Wasmtime before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 re-appends a trailing slash to rename source paths, causing renameat on macOS and FreeBSD hosts to follow directory symlinks. A guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox and read or write them.
- Record
DEBIAN-CVE-2026-118688- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-05
OSVRUSTSEC-2026-0352
Filesystem sandbox escape when renaming symlinks with trailing slashes
This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m9f7-9w4p-gv38 For more information see the GitHub-hosted security advisory.
- Record
RUSTSEC-2026-0352- CVSS 4.0
- 8.8 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
rust-wasmtimeDebian:13 |
All versions, plus listed versions 26.0.1+dfsg-1026.0.1+dfsg-326.0.1+dfsg-426.0.1+dfsg-526.0.1+dfsg-6 Show 39 moreShow less26.0.1+dfsg-726.0.1+dfsg-826.0.1+dfsg-927.0.0+dfsg-227.0.0+dfsg-327.0.0+dfsg-428.0.1+dfsg-128.0.1+dfsg-228.0.1+dfsg-329.0.1+dfsg-129.0.1+dfsg-229.0.1+dfsg-329.0.1+dfsg-429.0.1+dfsg-529.0.1+dfsg-629.0.1+dfsg-729.0.1+dfsg-836.0.11+dfsg-136.0.12+dfsg-136.0.12+dfsg-236.0.12+dfsg-336.0.13+dfsg-136.0.20+dfsg-136.0.5+dfsg-136.0.5+dfsg-236.0.5+dfsg-336.0.5+dfsg-436.0.5+dfsg-536.0.6+dfsg-136.0.6+dfsg-236.0.6+dfsg-336.0.6+dfsg-436.0.6+dfsg-536.0.6+dfsg-636.0.6+dfsg-736.0.7+dfsg-136.0.8+dfsg-136.0.9+dfsg-136.0.9+dfsg-2 |
None known |
rust-wasmtimeDebian:14 |
before 36.0.20+dfsg-1, plus listed versions 26.0.1+dfsg-1026.0.1+dfsg-326.0.1+dfsg-426.0.1+dfsg-526.0.1+dfsg-6 Show 38 moreShow less26.0.1+dfsg-726.0.1+dfsg-826.0.1+dfsg-927.0.0+dfsg-227.0.0+dfsg-327.0.0+dfsg-428.0.1+dfsg-128.0.1+dfsg-228.0.1+dfsg-329.0.1+dfsg-129.0.1+dfsg-229.0.1+dfsg-329.0.1+dfsg-429.0.1+dfsg-529.0.1+dfsg-629.0.1+dfsg-729.0.1+dfsg-836.0.11+dfsg-136.0.12+dfsg-136.0.12+dfsg-236.0.12+dfsg-336.0.13+dfsg-136.0.5+dfsg-136.0.5+dfsg-236.0.5+dfsg-336.0.5+dfsg-436.0.5+dfsg-536.0.6+dfsg-136.0.6+dfsg-236.0.6+dfsg-336.0.6+dfsg-436.0.6+dfsg-536.0.6+dfsg-636.0.6+dfsg-736.0.7+dfsg-136.0.8+dfsg-136.0.9+dfsg-136.0.9+dfsg-2 |
36.0.20+dfsg-1 |
wasmtime-wasicrates.io |
0.0.0-0 up to 36.0.18, 37.0.0 up to 48.0.6, 49.0.0 up to 49.0.3 | 36.0.1848.0.649.0.3 |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | EUVD | |
| affected | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-118688 is a high vulnerability (CVSS 8.8) in Bytecodealliance Wasmtime, published October 14, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.24%, the 15th percentile. Fixed in rust-wasmtime 36.0.20+dfsg-1.
References
github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m9f7-9w4p-gv38
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
nvd.nist.gov/vuln/detail/CVE-2026-118688
security-tracker.debian.org/tracker/CVE-2026-118688
crates.io/crates/wasmtime-wasi
rustsec.org/advisories/RUSTSEC-2026-0352.html