CVE-2026-115389

Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 Denial of Service via Val API

LOW
2.3
CVSS Score
Published: October 22, 2026 at 07:13 PM UTC
Updated: October 29, 2026 at 01:17 PM UTC
1 product affected across 1 vendorWasmtime

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Severity
LOW2.3
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

Wasmtime before 36.0.16, 37.0.0 before 48.0.3, and 49.0.0 before 49.0.1 does not adequately account for host allocations when lifting guest values through the dynamically-typed Val API, bypassing the hostcall fuel limit. A malicious WebAssembly guest can return crafted values that allocate at least ~100x more host memory than tracked, causing denial of service.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Vendor states this is fixed in 36.0.16 (unaffected)
Vendor states this is fixed in 48.0.3 (unaffected)
Vendor states this is fixed in 49.0.1 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

2.3LOWVulnCheck
Attack Vector
ADJACENT_NETWORK
Complexity
HIGH
Privileges
LOW
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
LOW
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-770

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