CVE-2026-115384
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 Stack Buffer Overflow
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 Stack Buffer Overflow
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
CVE-2026-115384- CVSS 4.0
- 9.4 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
EUVDEUVD-2026-108311
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
EUVD-2026-108311- CVSS 4.0
- 9.4 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-6fff-wrjr-wjxr
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow...
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
GHSA-6fff-wrjr-wjxr- CVSS 4.0
- 9.4 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
NVD
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
CVE-2026-115384- CVSS 4.0
- 9.4 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-20
- Updated
- 2026-11-02
OSV
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 Stack Buffer Overflow
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
CVE-2026-115384- CVSS 4.0
- 9.4 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - Weakness
- CWE-20
- Updated
- 2026-11-02
OSVRUSTSEC-2026-0327
Wasmtime component async-lifted callback result count is unvalidated, causing a native stack buffer overflow
This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-32h6-97mm-8q3c For more information see the GitHub-hosted security advisory.
- Record
RUSTSEC-2026-0327- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:H/VA:H/SC:L/SI:H/SA:H - Updated
- 2026-11-02
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OSVUBUNTU-CVE-2026-115384
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
UBUNTU-CVE-2026-115384- CVSS 4.0
- 9.4 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H - CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Updated
- 2026-11-05
OSVAZL-111011 No score
CVE-2026-115384 affecting package cloud-hypervisor 52.0.152-1
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
AZL-111011- Updated
- 2026-11-02
OSVAZL-111026 No score
CVE-2026-115384 affecting package openvmm 0.1.0-1
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
AZL-111026- Updated
- 2026-11-02
OSVAZL-111077 No score
CVE-2026-115384 affecting package rust 1.75.0-31
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
AZL-111077- Updated
- 2026-11-02
OSVAZL-111086 No score
CVE-2026-115384 affecting package rust 1.96.1-2
Wasmtime 39.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains a stack buffer overflow vulnerability that allows malicious guests to write ~16KB to the native stack via unvalidated async callback result types. Attackers can supply components with mistyped component-model-async callback functions to overwrite return addresses, crashing the host or escaping the sandbox.
- Record
AZL-111086- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
cloud-hypervisorAzure Linux:3 |
through 52.0.152-1 | None known |
openvmmAzure Linux:3 |
through 0.1.0-1 | None known |
rustAzure Linux:3 |
through 1.75.0-31 | None known |
rustAzure Linux:3 |
1.85.0 to 1.96.1-2 | None known |
wasmtimecrates.io |
39.0.0 up to 48.0.4, 49.0.0 up to 49.0.2 | 48.0.449.0.2 |
rust-wasmtimeUbuntu:26.10 |
All versions, plus listed versions 36.0.5+dfsg-136.0.13+dfsg-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected | OSV | |
| affected, facts | OSV | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-115384 is a critical vulnerability (CVSS 9.4) in Bytecodealliance Wasmtime, published October 2, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.31%, the 24th percentile. Fixed in wasmtime 48.0.4.
References
github.com/bytecodealliance/wasmtime/security/advisories/GHSA-32h6-97mm-8q3c
vulncheck.com/advisories/wasmtime-39.0.0-before-48.0.4-and-49.0.0-before-49.0.2-stack-buffer-overflow
nvd.nist.gov/vuln/detail/CVE-2026-115384
crates.io/crates/wasmtime