Wasmtime can panic when adding excessive fields to a `wasi:http/types.fields` instance
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 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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
wasmtimecrates.io | < 24.0.6 | 24.0.6 |
wasmtimecrates.io | >= 25.0.0, < 36.0.6 | 36.0.6 |
wasmtimecrates.io | >= 37.0.0, < 40.0.4 | 40.0.4 |
Affected products
10- osv-coords9 versionspkg:apk/chainguard/wasmcloudpkg:apk/chainguard/wizerpkg:apk/chainguard/yara-xpkg:apk/chainguard/zellijpkg:apk/wolfi/wasmcloudpkg:apk/wolfi/wizerpkg:apk/wolfi/yara-xpkg:apk/wolfi/zellijpkg:cargo/wasmtime
< 2.0.1-r0+ 8 more
- (no CPE)range: < 2.0.1-r0
- (no CPE)range: < 10.0.0-r7
- (no CPE)range: < 1.13.0-r2
- (no CPE)range: < 0.44.0-r0
- (no CPE)range: < 2.0.1-r0
- (no CPE)range: < 10.0.0-r7
- (no CPE)range: < 1.13.0-r2
- (no CPE)range: < 0.44.0-r0
- (no CPE)range: < 24.0.6
- Range: < 24.0.6
Patches
Vulnerability mechanics
References
10- github.com/advisories/GHSA-243v-98vx-264hghsaADVISORY
- nvd.nist.gov/vuln/detail/CVE-2026-27572ghsaADVISORY
- docs.rs/http/1.4.0/http/header/ghsax_refsource_MISCWEB
- github.com/bytecodealliance/wasmtime/commit/301dc7162cca51def19131019af1187f45901c0aghsax_refsource_MISCWEB
- github.com/bytecodealliance/wasmtime/releases/tag/v24.0.6ghsax_refsource_MISCWEB
- github.com/bytecodealliance/wasmtime/releases/tag/v36.0.6ghsax_refsource_MISCWEB
- github.com/bytecodealliance/wasmtime/releases/tag/v40.0.4ghsax_refsource_MISCWEB
- github.com/bytecodealliance/wasmtime/releases/tag/v41.0.4ghsax_refsource_MISCWEB
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-243v-98vx-264hghsax_refsource_CONFIRMWEB
- rustsec.org/advisories/RUSTSEC-2026-0021.htmlghsaWEB
News mentions
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