Use After Free in Bytecodealliance Wasmtime
CVE-2026-115379
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a missing GC rooting vulnerability that leaves references live across try_call unrooted when compiling Wasm modules. Attackers can supply Wasm modules whose callee triggers garbage collection, leaving stale or dangling references that cause GC heap corruption or incorrect execution.
Vulnerability class: Use-After-Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-hw8m-q44c-ggrf (vendor-advisory)
- www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.4-and-49.0.0-before-49… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-115379?
- CVE-2026-115379 is a medium-severity vulnerability in Bytecodealliance Wasmtime, classified under Use After Free. CVSS score: 5.7/10. Published 2026-10-22.
- How severe is CVE-2026-115379?
- Medium severity. CVSS v3 base score is 5.7 out of 10.