CVE-2026-121440
lowWasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 fails to check forwarded trailers against the WasiHttpHooks::is_forbidden_header hook in wasi-http p3.
Wasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 fails to check forwarded trailers against the WasiHttpHooks::is_forbidden_header hook in wasi-http p3. WASIp3 guests can forward a request or response body so its trailers skip embedder-customized forbidden header filtering, undermining header restrictions the embedder intended.
CVSS
3.7
3.7 (CVSS v3.1)
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N Severity source: NVD CVSS v3.1 (disclosure@vulncheck.com)
Timeline (UTC)
Published: 2026-11-03 15:17
Modified: 2026-11-03 19:18
NVD status: Deferred
Last synced 1 day ago
Verified against the source API 2026-11-03 19:20 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jxcf-8qw5-5c33 disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/wasmtime-46.0.0-before-48.0.7-and-49.0.0-before-49.0.... disclosure@vulncheck.com
Data sources
NVD CVE API 2.0 — fetched 2026-11-03 19:20 UTC · record ↗