What is CVE-2025-53901?

CVE-2025-53901 is a low-severity security vulnerability in wasmtime-wasi (rust), affecting versions < 24.0.4. It is fixed in 24.0.4, 33.0.2, 34.0.2.

How severe is CVE-2025-53901?

CVE-2025-53901 has a CVSS score of 3.5 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Which packages are affected by CVE-2025-53901?

wasmtime-wasi (rust) versions = 10.0.0, < 24.0.4.

Is there a fix for CVE-2025-53901?

Yes. CVE-2025-53901 is fixed in 24.0.4, 33.0.2, 34.0.2. Upgrade to this version or later.

Is CVE-2025-53901 exploitable, and should I be worried?

Whether CVE-2025-53901 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

What actually determines whether CVE-2025-53901 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2025-53901?

Upgrade: wasmtime-wasi to 24.0.4 or later, wasmtime-wasi to 33.0.2 or later, wasmtime-wasi to 34.0.2 or later, wasmtime to 24.0.4 or later, wasmtime to 33.0.2 or later, wasmtime to 34.0.2 or later.

CVE-2025-53901 in wasmtime-wasi | Intelligent Application Security

Q: How severe is CVE-2025-53901?

CVE-2025-53901 has a CVSS score of 3.5 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.

Q: Which packages are affected by CVE-2025-53901?

wasmtime-wasi (rust) versions = 10.0.0, < 24.0.4.

Q: Is there a fix for CVE-2025-53901?

Yes. CVE-2025-53901 is fixed in 24.0.4, 33.0.2, 34.0.2. Upgrade to this version or later.

Q: Is CVE-2025-53901 exploitable, and should I be worried?

Whether CVE-2025-53901 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk.

Q: What actually determines whether CVE-2025-53901 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

Q: How do I fix CVE-2025-53901?

Upgrade: wasmtime-wasi to 24.0.4 or later, wasmtime-wasi to 33.0.2 or later, wasmtime-wasi to 34.0.2 or later, wasmtime to 24.0.4 or later, wasmtime to 33.0.2 or later, wasmtime to 34.0.2 or later.

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.

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.

Impact

CVE-2025-53901 has a CVSS score of 3.5 (Low). The vector is network-reachable, low privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (24.0.4, 33.0.2, 34.0.2); upgrading removes the vulnerable code path.

Affected versions

wasmtime-wasi (< 24.0.4) wasmtime-wasi (>= 25.0.0, < 33.0.2) wasmtime-wasi (>= 34.0.0, < 34.0.2) wasmtime (>= 10.0.0, < 24.0.4) wasmtime (>= 33.0.0, < 33.0.2) wasmtime (>= 34.0.0, < 34.0.2)

Security releases

wasmtime-wasi → 24.0.4 (rust) wasmtime-wasi → 33.0.2 (rust) wasmtime-wasi → 34.0.2 (rust) wasmtime → 24.0.4 (rust) wasmtime → 33.0.2 (rust) wasmtime → 34.0.2 (rust)

Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.

See it in your environment

Remediation advice

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.

Frequently Asked Questions

What is CVE-2025-53901? CVE-2025-53901 is a low-severity security vulnerability in wasmtime-wasi (rust), affecting versions < 24.0.4. It is fixed in 24.0.4, 33.0.2, 34.0.2.
How severe is CVE-2025-53901? CVE-2025-53901 has a CVSS score of 3.5 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
Which packages are affected by CVE-2025-53901?
- wasmtime-wasi (rust) (versions < 24.0.4)
- wasmtime (rust) (versions >= 10.0.0, < 24.0.4)
Is there a fix for CVE-2025-53901? Yes. CVE-2025-53901 is fixed in 24.0.4, 33.0.2, 34.0.2. Upgrade to this version or later.
Is CVE-2025-53901 exploitable, and should I be worried? Whether CVE-2025-53901 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
What actually determines whether CVE-2025-53901 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
How do I fix CVE-2025-53901?
- Upgrade wasmtime-wasi to 24.0.4 or later
- Upgrade wasmtime-wasi to 33.0.2 or later
- Upgrade wasmtime-wasi to 34.0.2 or later
- Upgrade wasmtime to 24.0.4 or later
- Upgrade wasmtime to 33.0.2 or later
- Upgrade wasmtime to 34.0.2 or later

Other vulnerabilities in wasmtime-wasi

CVE-2025-53901