CVE-2026-121440

medium

Description

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.

References

https://www.vulncheck.com/advisories/wasmtime-46.0.0-before-48.0.7-and-49.0.0-before-49.0.4-forwarded-trailers-header-filter-bypass

https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-jxcf-8qw5-5c33

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-115862

Details

Source: Mitre, NVD

Published: 2026-11-03

Updated: 2026-11-03

Risk Information

CVSS v2

Base Score: 2.6

Vector: CVSS2#AV:N/AC:H/Au:N/C:N/I:P/A:N

Severity: Low

CVSS v3

Base Score: 3.7

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Severity: Low

CVSS v4

Base Score: 6.3

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Severity: Medium

EPSS

EPSS: 0.00224