◆ CVE Hub

CVE-2026-115893

Wasmtime: Cranelift backend on aarch64 can jump to incorrect target on large Wasm `br_table` instruction

Published
2026-10-23
Last modified
2026-10-23
CNA
GitHub_M
NVD status
Deferred
CWE
CWE-691

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CVSS v3.1 (listed by NVD)
9.9
CRITICAL
Scored by github.com (not yet scored by NVD)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0 (listed by NVD)
—
Not scored
CVSS (listed by CVE.org)
9.9
CRITICAL
Scored by CNA (GitHub_M) · v3.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS exploit probability
0.8%
Percentile 55.9%
as of 2026-10-24
CISA KEV
—
Not listed

Attack conditions and impact

Derived from the CNA (via NVD) CVSS 3.1 vector
NetworkLoginNo interaction Scope change Confidentiality HIntegrity HAvailability H
MetricValueMeaning
Attack vector AVNNetwork
Attack complexity ACLLow (easy)
Privileges required PRLRegular user
User interaction UINNone
Scope SCChanged (affects other components)
Confidentiality CHHigh
Integrity IHHigh
Availability AHHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Description

NVD

Wasmtime is a runtime for WebAssembly. Prior to 36.0.19, 48.0.7, and 49.0.4, the Cranelift compiler backend on aarch64 can compile a Wasm br_table instruction with more than approximately 256,000 targets so that it has an incorrect conditional branch target. The branch can then jump to arbitrary other code at a user-controlled offset, allowing a user-controlled Wasm module to escape the sandbox on aarch64 engines using the default Cranelift backend. This issue is fixed in versions 36.0.19, 48.0.7, and 49.0.4.

CVSS assessments

ProviderVersionScoreVector
NVD / [email protected] (Secondary)3.19.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CNA / GitHub_M3.19.9 CRITICALCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Affected products and packages

CNA (CVE.org)

VendorProductVersions
bytecodealliancewasmtime
affected: < 36.0.19
affected: >= 37.0.0, < 48.0.7
affected: >= 49.0.0, < 49.0.4

Open-source packages (GitHub Advisory / OSV)

RUSTSEC-2026-0379 OSV

Cranelift backend on aarch64 can jump to incorrect target on large Wasm `br_table` instruction

EcosystemPackageAffected versionsFixed in
crates.iowasmtime>= 0.0.0-0, < 36.0.19; >= 37.0.0, < 48.0.7; >= 49.0.0, < 49.0.436.0.19, 48.0.7, 49.0.4

Linux distribution status

Red Hat ↗ Fetching

Debian ↗

ReleasePackageStatusFixed version / notes
forkyrust-wasmtimeopen not yet assigned
sidrust-wasmtimeopen not yet assigned
trixierust-wasmtimeopen not yet assigned

Ubuntu ↗ Fetching

References (14)