CVE-2026-115383
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 GC Heap Corruption via Tag Imports
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 GC Heap Corruption via Tag Imports
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
CVE-2026-115383- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H - Weakness
- CWE-1287
- Updated
- 2026-11-04
EUVDEUVD-2026-108309
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
EUVD-2026-108309- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-04
GitHub AdvisoriesGHSA-cvpp-75f3-xc4p
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation...
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
GHSA-cvpp-75f3-xc4p- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H - Weakness
- CWE-1287
- Updated
- 2026-11-02
NVD
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
CVE-2026-115383- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/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
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H - Weakness
- CWE-1287
- Updated
- 2026-11-04
OSV
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 GC Heap Corruption via Tag Imports
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
CVE-2026-115383- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-1287
- Updated
- 2026-11-05
OSVRUSTSEC-2026-0325
Mis-typed WebAssembly tag imports can lead to GC heap corruption
This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-cfhf-m2cr-62wj For more information see the GitHub-hosted security advisory.
- Record
RUSTSEC-2026-0325- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
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OSVUBUNTU-CVE-2026-115383
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
UBUNTU-CVE-2026-115383- CVSS 4.0
- 5.9 Medium
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVAZL-111008 No score
CVE-2026-115383 affecting package cloud-hypervisor 52.0.152-1
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
AZL-111008- Updated
- 2026-11-05
OSVAZL-111029 No score
CVE-2026-115383 affecting package openvmm 0.4.0-1
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
AZL-111029- Updated
- 2026-11-05
OSVAZL-111083 No score
CVE-2026-115383 affecting package rust 1.75.0-31
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
AZL-111083- Updated
- 2026-11-02
OSVAZL-111089 No score
CVE-2026-115383 affecting package rust 1.98.1-1
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
- Record
AZL-111089- Updated
- 2026-11-05
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
cloud-hypervisorAzure Linux:3 |
through 52.0.152-1 | None known |
openvmmAzure Linux:3 |
through 0.4.0-1 | None known |
rustAzure Linux:3 |
through 1.75.0-31 | None known |
rustAzure Linux:3 |
1.85.0 to 1.98.1-1 | None known |
wasmtimecrates.io |
47.0.0 up to 48.0.4, 49.0.0 up to 49.0.2 | 48.0.449.0.2 |
rust-wasmtimeUbuntu:24.04:LTS |
All versions, plus listed versions 10.0.1+dfsg-715.0.1+dfsg-416.0.0+dfsg-216.0.0+dfsg-3 |
None known |
rust-wasmtimeUbuntu:26.10 |
All versions, plus listed versions 36.0.5+dfsg-136.0.13+dfsg-1 |
None known |
rust-wasmtimeUbuntu:26.04:LTS |
All versions, plus listed versions 26.0.1+dfsg-326.0.1+dfsg-428.0.1+dfsg-329.0.1+dfsg-536.0.5+dfsg-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| facts | EUVD | |
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-115383 is a medium vulnerability (CVSS 5.9) 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 0.18%, the 7th percentile. Fixed in wasmtime 48.0.4.
References
github.com/bytecodealliance/wasmtime/security/advisories/GHSA-cfhf-m2cr-62wj
vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.4-and-49.0.0-before-49.0.2-gc-heap-corruption-via-tag-imports
nvd.nist.gov/vuln/detail/CVE-2026-115383
crates.io/crates/wasmtime