Bytecode Alliance Wasmtime up to 36.0.18/48.0.6/49.0.3 Cranelift compiler backend br_table privileges management

Summaryinfo

A vulnerability marked as critical has been reported in Bytecode Alliance Wasmtime up to 36.0.18/48.0.6/49.0.3. This issue affects the function br_table of the component Cranelift compiler backend. Performing a manipulation results in privileges management. This vulnerability is known as CVE-2026-115893. Remote exploitation of the attack is possible. No exploit is available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Bytecode Alliance Wasmtime up to 36.0.18/48.0.6/49.0.3. This affects the function br_table of the component Cranelift compiler backend. The manipulation with an unknown input leads to a privileges management vulnerability. CWE is classifying the issue as CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-115893 since 10/23/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Technical details are known, but no exploit is available. MITRE ATT&CK project uses the attack technique T1068 for this issue.

Upgrading to version 36.0.19, 48.0.7 or 49.0.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-109188). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

• Bytecode Alliance

Name

• Wasmtime

Version

• 36.0.0
• 36.0.1
• 36.0.2
• 36.0.3
• 36.0.4
• 36.0.5
• 36.0.6
• 36.0.7
• 36.0.8
• 36.0.9
• 36.0.10
• 36.0.11
• 36.0.12
• 36.0.13
• 36.0.14
• 36.0.15
• 36.0.16
• 36.0.17
• 36.0.18
• 48.0.0
• 48.0.1
• 48.0.2
• 48.0.3
• 48.0.4
• 48.0.5
• 48.0.6
• 49.0.0
• 49.0.1
• 49.0.2
• 49.0.3

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion