bytecodealliance wasmtime up to 24.0.5/36.0.5/40.0.3/41.0.3 allocation of resources

Summaryinfo

A vulnerability marked as problematic has been reported in bytecodealliance wasmtime up to 24.0.5/36.0.5/40.0.3/41.0.3. This affects an unknown function. The manipulation leads to allocation of resources. This vulnerability is traded as CVE-2026-27572. It is possible to initiate the attack remotely. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in bytecodealliance wasmtime up to 24.0.5/36.0.5/40.0.3/41.0.3 and classified as problematic. This issue affects an unknown code. The manipulation with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Impacted is availability. The summary by CVE is:

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 the `wasi:http/types.fields` resource is susceptible to panics when too many fields are added to the set of headers. Wasmtime's implementation in the `wasmtime-wasi-http` crate is backed by a data structure which panics when it reaches excessive capacity and this condition was not handled gracefully in Wasmtime. Panicking in a WASI implementation is a Denial of Service vector for embedders and is treated as a security vulnerability in Wasmtime. Wasmtime 24.0.6, 36.0.6, 40.0.4, 41.0.4, and 42.0.0 patch this vulnerability and return a trap to the guest instead of panicking. There are no known workarounds at this time. Embedders are encouraged to update to a patched version of Wasmtime.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-27572 since 02/20/2026. The exploitation is known to be easy. The attack may be initiated remotely. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 300029 (Linux Distros Unpatched Vulnerability : CVE-2026-27572), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 24.0.6, 36.0.6, 40.0.4 or 41.0.4 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 301dc7162cca51def19131019af1187f45901c0a is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (300029). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Vendor

• bytecodealliance

Name

• wasmtime

Version

• 24.0.0
• 24.0.1
• 24.0.2
• 24.0.3
• 24.0.4
• 24.0.5
• 36.0.0
• 36.0.1
• 36.0.2
• 36.0.3
• 36.0.4
• 36.0.5
• 40.0.0
• 40.0.1
• 40.0.2
• 40.0.3
• 41.0.0
• 41.0.1
• 41.0.2
• 41.0.3

License

• open-source

Website

• Product: https://github.com/bytecodealliance/wasmtime/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion