CVE-2026-27204
Wasmtime WASI implementations are vulnerable to guest-controlled resource exhaustion
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Timeline
ID reserved
By GitHub_M
- 6 days later
· 6 days later
Published
- 3 days later
· 3 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 4.0 | Medium6.9 | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H |
| NVDNVD · Analyzed | 4.0 | Medium6.9 | CVSS: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:X |
- EPSS (exploitation in 30 days)
- 0.40% · top 65% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.9.
Weakness
- CWE-400: Uncontrolled Resource Consumption (opens in a new tab)All about CWE-400 and its CVEs
- CWE-770: Allocation of Resources Without Limits or Throttling (opens in a new tab)All about CWE-770 and its CVEs
- CWE-774: Allocation of File Descriptors or Handles Without Limits or Throttling (opens in a new tab)All about CWE-774 and its CVEs
- CWE-789: Memory Allocation with Excessive Size Value (opens in a new tab)All about CWE-789 and its CVEs
Affected products
- affected < 24.0.6
- affected >= 25.0.0, < 36.0.6
- affected >= 37.0.0, < 40.0.4
- affected >= 41.0.0, < 41.0.4
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- crates.iowasmtimeGHSA-852m-cvvp-9p4w (opens in a new tab)
References (7)
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-852m-cvvp-9p4w (opens in a new tab)x_refsource_CONFIRM
- https://github.com/bytecodealliance/wasmtime/issues/11552 (opens in a new tab)x_refsource_MISC
- https://github.com/bytecodealliance/wasmtime/pull/12599 (opens in a new tab)x_refsource_MISC
- https://docs.rs/wasmtime-wasi/latest/wasmtime_wasi/struct.WasiCtxBuilder.html#method.max_random_size (opens in a new tab)x_refsource_MISC
- https://docs.rs/wasmtime/latest/wasmtime/component/struct.ResourceTable.html#method.set_max_capacity (opens in a new tab)x_refsource_MISC
- https://docs.rs/wasmtime/latest/wasmtime/struct.Store.html#method.set_hostcall_fuel (opens in a new tab)x_refsource_MISC
- https://docs.wasmtime.dev/security-what-is-considered-a-security-vulnerability.html (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-852m-cvvp-9p4w (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-27204)Record last updated .