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RUSTSEC-2026-0323 CVE-2026-115386 GHSA-96f6-r43r-8c24

fd_readdir copies uninitialized struct padding into guest memory

Low crates.io
Severity
0.0 / 10
Low · CVSS 4.0
Exploit chance (EPSS)
0.20%
Chance of exploitation in the next 30 days. Higher than 9.53% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-908 Use of Uninitialized Resource
Fix
49.0.2
Upgrade wasmtime-wasi to this version or later

Description

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-96f6-r43r-8c24 For more information see the GitHub-hosted security advisory.

Affected versions

crates.io

PackageVulnerableFixed in
wasmtime-wasi
>= 0.0.0-0, < 36.0.17
>= 37.0.0, < 48.0.4
>= 49.0.0, < 49.0.2
36.0.17
48.0.4
49.0.2

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-wasi crates.io → 49.0.2

cargo
cargo update -p wasmtime-wasi --precise 49.0.2

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
Low
User interaction
Passive
Confidentiality (vulnerable system)
Low
Integrity (vulnerable system)
None
Availability (vulnerable system)
None
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 2.6

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N

Attack vector
Network
Attack complexity
High
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None

Weakness

CWE-908: Use of Uninitialized Resource

The product uses or accesses a resource that has not been initialized.

How to prevent it
  • Implementation: Explicitly initialize the resource before use. If this is performed through an API function or standard procedure, follow all required steps.
  • Implementation: Pay close attention to complex conditionals that affect initialization, since some branches might not perform the initialization.
  • Implementation: Avoid race conditions (CWE-362) during initialization routines.
  • Build and Compilation: Run or compile the product with settings that generate warnings about uninitialized variables or data.

References

Advisories

Packages

Other links

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
RUSTSEC-2026-0420
wasip3 UDP `send` can deliver a datagram to an address only allowed for receiving
Medium Also affects wasmtime-wasi
RUSTSEC-2026-0352
Filesystem sandbox escape when renaming symlinks with trailing slashes
Not rated yet Also affects wasmtime-wasi
RUSTSEC-2026-0324
Guest can panic host through filesystem timestamp before the epoch on wasip3
Medium Also affects wasmtime-wasi
RUSTSEC-2026-0321
WASI preview 0 implementation of `poll_oneoff` circumvents fuel consumption
Medium Also affects wasmtime-wasi
RUSTSEC-2026-0322
Excessive allocated memory on the host when guests don't have stdio
Medium Also affects wasmtime-wasi
RUSTSEC-2026-0314
Guest can panic host through filesystem datetime overflow
Medium Also affects wasmtime-wasi
GHSA-4ch3-9j33-3pmj
Wasmtime: WASI hard links bypass wasmtime-wasi's FilePerms for destination
Medium Also affects wasmtime-wasi
GHSA-3p27-qvp9-27qf
Wasmtime has a leak in WASIp1 `fd_renumber` implementation
Medium Also affects wasmtime-wasi
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