Wasmtime WASI implementations are vulnerable to guest-controlled resource exhaustion (bytecodealliance wasmtime)

CVE-2026-27204
MEDIUM 6.9

At a glance

Source
NVD
EPSS
EPSS 0.40 % Β· percentile 35 ()
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
NVD status
Analyzed

Description

Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.6, 36.0.6, 4.0.04, 41.0.4, and 42.0.0, Wasmtime's implementation of WASI host interfaces are susceptible to guest-controlled resource exhaustion on the host. Wasmtime did not appropriately place limits on resource allocations requested by the guests. This serves as a Denial of Service vector. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 have all been released with the fix for this issue. These versions do not prevent this issue in their default configuration to avoid breaking preexisting behaviors. All versions of Wasmtime have appropriate knobs to prevent this behavior, and Wasmtime 42.0.0-and-later will have these knobs tuned by default to prevent this issue from happening. There are no known workarounds for this issue without upgrading. Embedders are recommended to upgrade and configure their embeddings as necessary to prevent possibly-malicious guests from triggering this issue.

Weaknesses (CWE)

  • CWE-400 β€” Uncontrolled Resource Consumption
  • CWE-770 β€” Allocation of Resources Without Limits or Throttling
  • CWE-774 β€” Allocation of File Descriptors or Handles Without Limits or Throttling
  • CWE-789 β€” Memory Allocation with Excessive Size Value

References

Scores

VersionScoreVectorScored by
CVSS 4.0MEDIUM 6.9CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:HGitHub_M
CVSS 4.0MEDIUM 6.9CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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:XNVD Β· security-advisories@github.com (Secondary)
CVSS 3.1MEDIUM 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD Β· nvd@nist.gov (Primary)

European references

Affected configurations (NVD CPE)

Affected products

ProductVersions
bytecodealliance Β· wasmtimeaffected < 24.0.6 ; affected >= 25.0.0, < 36.0.6 ; affected >= 37.0.0, < 40.0.4 ; affected >= 41.0.0, < 41.0.4

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST β€” attribution requested
ENISA EUVDENISA β€” reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain β€” this product uses data from the NVD API but is not endorsed or certified by the NVD