CVE-2026-115379: Use After Free in bytecodealliance wasmtime
Description
CVE-2026-115379 is a use-after-free vulnerability in bytecodealliance's wasmtime affecting versions 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2. The flaw involves missing garbage collection rooting that leaves references unrooted across try_call when compiling WebAssembly modules. This can cause garbage collection heap corruption or incorrect execution when attackers supply specially crafted Wasm modules.
CVSS v4.0
Score 6.9medium
Affected software
bytecodealliance
wasmtime
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in wasmtime versions >=47.0.0 <48.0.4 and >=49.0.0 <49.0.2 is due to missing garbage collection rooting of references that remain live across try_call during WebAssembly module compilation. Attackers can exploit this by providing Wasm modules whose callee triggers garbage collection, resulting in stale or dangling references. This leads to use-after-free conditions causing GC heap corruption or incorrect execution of code.
Potential Impact
Successful exploitation can cause heap corruption in the garbage collector or incorrect execution of WebAssembly modules. This may lead to application instability or potential execution of unintended code paths. The CVSS 4.0 score of 6.9 indicates a medium severity with network attack vector, low attack complexity, and no privileges required but user interaction needed.
Mitigation Recommendations
A fix is available in wasmtime versions 48.0.4 and 49.0.2 and later. Users should upgrade to these or newer versions to remediate this vulnerability. No additional mitigation steps are indicated in the provided data.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-22T11:25:27.610Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ada64a24d27ba8daa755e76
Added to database: 10/22/2026, 19:31:46 UTC
Last enriched: 10/22/2026, 20:31:32 UTC
Last updated: 10/22/2026, 20:31:32 UTC
Views: 3
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