Dashboard / CVE-2026-121440

CVE-2026-121440

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 63/100
Published: 2026-11-03 Modified: 2026-11-03 First seen: 2026-11-03 Status: active

Attack Surface

Network No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: High
PR: None
UI: None
S: X
AT: Present
VC: None
VI: Low
VA: None

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.

Weakness Classification (1)

Affected Software (4)

VendorProductVersion
bytecodealliance wasmtime 46.0.0 < 48.0.7
bytecodealliance wasmtime 49.0.0 < 49.0.4
bytecodealliance wasmtime 46.0.0 < 48.0.7
bytecodealliance wasmtime 49.0.0 < 49.0.4

References & Advisories (2)

Bug Bounty Relevance

63 / 100
✓ Network accessible
✓ No authentication
✓ No user interaction

CVSS Score

6.3 / 10.0 v4.0
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.22%
Raw Score 0.002240
Percentile 13.2%
Date 2026-11-14

EPSS Trend

2026-11-14
0.00224
2026-11-13
0.00224
2026-11-12
0.00224
2026-11-10
0.00224
2026-11-09
0.00224
2026-11-08
0.00224
2026-11-07
0.00224
2026-11-06
0.00224
2026-11-05
0.00224
2026-11-04
0.00224

Intelligence Sources

mitre ref →
nvd ref →

External Links