Dashboard / CVE-2026-121439

CVE-2026-121439

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 74/100
Published: 2026-11-03 Modified: 2026-11-09 First seen: 2026-11-03 Status: active

Attack Surface

Network Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: None
AT: None
VC: None
VI: Low
VA: None

Description

Wasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 contains a response splitting vulnerability in wasi-http p3 that allows guests to set unvalidated content-length headers. Malicious wasip3 guests can splice an existing body into a new response with an incorrect content-length to perform response splitting or injection attacks.

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

74 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

6.9 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

EPSS — Exploitation Probability

0.19%
Raw Score 0.001930
Percentile 9.1%
Date 2026-11-14

EPSS Trend

2026-11-14
0.00193
2026-11-13
0.00193
2026-11-12
0.00193
2026-11-10
0.00193
2026-11-09
0.00193
2026-11-08
0.00193
2026-11-07
0.00193
2026-11-06
0.00193
2026-11-05
0.00193
2026-11-04
0.00193

Intelligence Sources

mitre ref →
nvd ref →

External Links