Rust advisories / wasmtime-wasi-http
Vulnerability LowRUSTSEC-2026-0376 · wasmtime-wasi-http
RUSTSEC-2026-0376: `wasi-http`: Guests can add conflicting content lengths to messages
Short answerA security vulnerability in the wasmtime-wasi-http crate: `wasi-http`: Guests can add conflicting content lengths to messages. Low severity (CVSS 3.7). Fixed in 36.0.19, 48.0.7, 49.0.4: update to a fixed version.
| Crate | wasmtime-wasi-http |
|---|---|
| Type | Vulnerability |
| Affected versions | Before 36.0.19; from 37.0.0 before 48.0.7; from 49.0.0 before 49.0.4. |
| Fixed in | 36.0.19, 48.0.7, 49.0.4 |
| Severity | Low, CVSS 3.7 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N |
| Published | 2026-10-19 |
| Last changed | 2026-10-20 |
| Also known as | GHSA-r8xh-cgf7-392j |
What to do
- See which version you have:
cargo tree -i wasmtime-wasi-http(it also shows which of your dependencies pulls it in). - Update within your version requirement:
cargo update -p wasmtime-wasi-http. If the fix is a newer major or minor than your requirement allows, raise it in Cargo.toml (for examplewasmtime-wasi-http = "49.0.4") or update the dependency that pulls it in. - Check again with
cargo audit, or paste your Cargo.lock into our Cargo.toml checker.
Details from the advisory
This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-r8xh-cgf7-392j For more information see the GitHub-hosted security advisory.
References
- Package: crates.io/crates/wasmtime-wasi-http
- Advisory: rustsec.org/advisories/RUSTSEC-2026-0376.html
- Web: github.com/bytecodealliance/wasmtime/pull/14824
From the RustSec Advisory Database (CC0-1.0) via the OSV export, downloaded Oct 24, 2026. Severity score computed from the published CVSS vector.
Other advisories for wasmtime-wasi-http
- Vulnerability MediumRUSTSEC-2026-0313 · 2026-09-24Outgoing HTTP body write allows guest-driven host memory exhaustion
- VulnerabilityRUSTSEC-2026-0320 · 2026-10-02Wasmtime wasi:http implementation panics with a zero timeout supplied
- VulnerabilityRUSTSEC-2026-0350 · 2026-10-14Guests can send absolute-form HTTP requests to different hosts
- Vulnerability MediumRUSTSEC-2026-0351 · 2026-10-14`wasi-http`: Request with long url before query parameter crashes host
- Vulnerability MediumRUSTSEC-2026-0375 · 2026-10-19`wasi-http` p3: Guests can set incorrect content-length for spliced response bodies
- Vulnerability LowRUSTSEC-2026-0377 · 2026-10-19`wasi-http` p3: forwarded trailers aren't checked against `is_forbidden_header` hook
Up next
Same cratewasmtime-wasi-http: security historyEvery advisory for this crate, and whether it is safe to use today.Read it next →Did this answer your question?