GHSA-fm79-3f68-h2fc CVE-2025-53901 RUSTSEC-2025-0046
Wasmtime CLI is vulnerable to host panic through its fd_renumber function
- Severity
- 3.5 / 10
- Low · CVSS 3.1
- Exploit chance (EPSS)
- 0.38%
- Chance of exploitation in the next 30 days. Higher than 32.09% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-672 Operation on a Resource after Expiration or Release
- Fix
- Available
- 2 packages have a fixed version
Description
Summary
A bug in Wasmtime's implementation of the WASIp1 set of import functions can lead to a WebAssembly guest inducing a panic in the host (embedder).
The specific bug is triggered by calling path_open after calling fd_renumber with either:
- two equal argument values
- second argument being equal to a previously-closed file descriptor number value
The corrupt state introduced in fd_renumber will lead to the subsequent opening of a file descriptor to panic. This panic cannot introduce memory unsafety or allow WebAssembly to break outside of its sandbox, however. There is no possible heap corruption or memory unsafety from this panic.
This bug is in the implementation of Wasmtime's wasmtime-wasi crate which provides an implementation of WASIp1. The bug requires a specially crafted call to fd_renumber in addition to the ability to open a subsequent file descriptor. Opening a second file descriptor is only possible when a preopened directory was provided to the guest, and this is common amongst embeddings. A panic in the host is considered a denial-of-service vector for WebAssembly embedders and is thus a security issue in Wasmtime.
This bug does not affect WASIp2 and embedders using components.
Patches
In accordance with Wasmtime's release process patch releases are available as 24.0.4, 33.0.2, and 34.0.2. Users of other release of Wasmtime are recommended to move to a supported release of Wasmtime.
Workarounds
Embedders who are using components or are not providing guest access to create more file descriptors (e.g. via a preopened filesystem directory) are not affected by this issue. Otherwise there is no workaround at this time and affected embeddings are recommended to update to a patched version which will not cause a panic in the host.
Affected versions
crates.io
| Package | Vulnerable | Fixed in |
|---|---|---|
| wasmtime | >= 10.0.0, < 24.0.4 |
24.0.4 |
| wasmtime | >= 33.0.0, < 33.0.2 |
33.0.2 |
| wasmtime | >= 34.0.0, < 34.0.2 |
34.0.2 |
| wasmtime | >= 10.0.0, < 24.0.4>= 25.0.0, < 33.0.2>= 34.0.0, < 34.0.2 |
24.0.433.0.234.0.2 |
| wasmtime-wasi | < 24.0.4 |
24.0.4 |
| wasmtime-wasi | >= 25.0.0, < 33.0.2 |
33.0.2 |
| wasmtime-wasi | >= 34.0.0, < 34.0.2 |
34.0.2 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
wasmtime crates.io → 24.0.4
- cargo
cargo update -p wasmtime --precise 24.0.4
wasmtime-wasi crates.io → 24.0.4
- cargo
cargo update -p wasmtime-wasi --precise 24.0.4
Severity breakdown
CVSS 3.1 3.5
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- Low
Weakness
CWE-672: Operation on a Resource after Expiration or Release
The product uses, accesses, or otherwise operates on a resource after that resource has been expired, released, or revoked.
References
Advisories
Packages
Other links
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-fm79-3f68-h2fc
- github.com/bytecodealliance/wasmtime/pull/11277
- github.com/bytecodealliance/wasmtime/pull/11278
- github.com/bytecodealliance/wasmtime/pull/11279
- github.com/bytecodealliance/wasmtime/pull/11281
- docs.wasmtime.dev/security-what-is-considered-a-security-vulnerability.html
- docs.wasmtime.dev/stability-release.html
- github.com/WebAssembly/WASI/blob/e1aa1cae4dda4c1f70f23fe11e922aae92f240a8/legac…
- github.com/bytecodealliance/wasmtime/blob/037a6edadbc225decbea00a551aabf0420371…
- rustsec.org/advisories/RUSTSEC-2025-0046.html
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| RUSTSEC-2026-0424 Unchecked memory usage in transferring borrowed resources between components | Not rated yet | Also affects wasmtime |
| RUSTSEC-2026-0423 Cross-engine type confusion with host-created struct-types-with-supertypes | Not rated yet | Also affects wasmtime |
| RUSTSEC-2026-0422 Typed functions with `i31` or `nullref` arguments may panic due to insufficient type-check | Low | Also affects wasmtime |
| RUSTSEC-2026-0420 wasip3 UDP `send` can deliver a datagram to an address only allowed for receiving | Medium | Also affects wasmtime-wasi |
| RUSTSEC-2026-0379 Wasmtime: Cranelift backend on aarch64 can jump to incorrect target on large Wasm `br_table` instruction | Critical | Also affects wasmtime |
| GHSA-9pvw-hwfg-92h5 Wasmtime: Panic lowering a host-created component model stream into a guest that expects a different payload type | Medium | Also affects wasmtime |
| GHSA-897f-g5gm-fmxm Wasmtime: Bit-packing in Cranelift compiler causes silent overflow and miscompilation | Critical | Also affects wasmtime |
| RUSTSEC-2026-0352 Filesystem sandbox escape when renaming symlinks with trailing slashes | Not rated yet | Also affects wasmtime-wasi |
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