Dashboard / CVE-2026-34945

CVE-2026-34945

LOW
INFO Priority: 0.01 BB Relevance: 55/100
Published: 2026-04-09 Modified: 2026-10-26 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction

CVSS Vector Breakdown

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

Description

Wasmtime is a runtime for WebAssembly. From 25.0.0 to before 36.0.7, 42.0.2, and 43.0.1, Wasmtime's Winch compiler contains a bug where a 64-bit table, part of the memory64 proposal of WebAssembly, incorrectly translated the table.size instruction. This bug could lead to disclosing data on the host's stack to WebAssembly guests. The host's stack can possibly contain sensitive data related to other host-originating operations which is not intended to be disclosed to guests. This bug specifically arose from a mistake where the return value of table.size was statically typed as a 32-bit integer, as opposed to consulting the table's index type to see how large the returned register could be. When combined with details about Wnich's ABI, such as multi-value returns, this can be combined to read stack data from the host, within a guest. This vulnerability is fixed in 36.0.7, 42.0.2, and 43.0.1.

Weakness Classification (1)

Affected Software (1)

VendorProductVersion
bytecodealliance wasmtime 25.0.0 – 36.0.7

References & Advisories (1)

Bug Bounty Relevance

55 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

2.3 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:L/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

0.32%
Raw Score 0.003240
Percentile 25.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00324
2026-10-28
0.00324

Intelligence Sources

nvd ref →

External Links