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Low, CVSS 3.5

Wasmtime CLI is vulnerable to host panic through its fd_renumber function

CVE-2025-53901GHSA-fm79-3f68-h2fc

What to do

Vendor fix available. Upgrade each affected package to the fixed version on its release line (wasmtime-wasi 34.0.2, 33.0.2, 24.0.4; wasmtime 34.0.2, 33.0.2, 24.0.4), redeploy, then verify what is actually installed.

This page has no inventory attached, so it cannot say whether you are affected. A vendor fix is not proof that your deployment is fixed.

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Affected packages

  • crates.io wasmtime-wasi

    Affected
    < 24.0.4>= 25.0.0, < 33.0.2>= 34.0.0, < 34.0.2
    Fixed in
    24.0.4, 34.0.2, 33.0.2

  • crates.io wasmtime

    Affected
    >= 10.0.0, < 24.0.4>= 33.0.0, < 33.0.2>= 34.0.0, < 34.0.2
    Fixed in
    24.0.4, 34.0.2, 33.0.2

Sources

Severity and exploitation
Exploitation
No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.
CVSS
3.5 · CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
EPSS
  • CVE-2025-53901: 0.38% estimated exploitation activity in the next 30 days; percentile 32.13 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.
Source description

As published by the source; long descriptions are shortened.

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 pathopen after calling fdrenumber with either: - two equal argument values - second argument being equal to a previously-closed file descriptor number value The corrupt state introduced in fdrenumber 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 fdrenumber 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…

Dates and revisions
Published by the source
Last modified by the source
Source last checked
  1. Revision 1 · created ·

    Published from ghsa record GHSA-fm79-3f68-h2fc

Agent brief

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# Patch Next advisory brief: CVE-2025-53901

Advisory: Wasmtime CLI is vulnerable to host panic through its fd_renumber function
IDs: CVE-2025-53901, GHSA-fm79-3f68-h2fc
Record: https://patchnext.com/advisories/cve-2025-53901 (revision 1, source checked 26 Oct 2026, 15:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 3.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: wasmtime-wasi 34.0.2, 33.0.2, 24.0.4; wasmtime 34.0.2, 33.0.2, 24.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io wasmtime-wasi: affected < 24.0.4; >= 25.0.0, < 33.0.2; >= 34.0.0, < 34.0.2; fixed in 24.0.4, 34.0.2, 33.0.2
- crates.io wasmtime: affected >= 10.0.0, < 24.0.4; >= 33.0.0, < 33.0.2; >= 34.0.0, < 34.0.2; fixed in 24.0.4, 34.0.2, 33.0.2

## Suggested inspection (read-only)
- crates.io wasmtime-wasi: check the installed version with your package manager.
- crates.io wasmtime: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on wasmtime-wasi, wasmtime.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-fm79-3f68-h2fc (GitHub-reviewed advisory GHSA-fm79-3f68-h2fc lists affected ranges: crates.io wasmtime-wasi >=0 =25.0.0 =34.0.0 =10.0.0 =33.0.0 =34.0.0 <34.0.2)

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