CVE-2026-126408
Wasmtime 47.0.0 before 48.0.8 Denial of Service via TypedFunc Type-Check Panic
Description
Wasmtime 47.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains an insufficient type-check in the TypedFunc embedder API for I31, Option<I31>, and Option<NoneRef> parameter or result types, reaching an unreachable!() path. A malicious guest module exporting a function that uses another anyref-hierarchy type can panic the host embedding, causing denial of service.
INFO
Published Date :
Nov. 13, 2026, 10:17 a.m.
Last Modified :
Nov. 13, 2026, 9:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | LOW | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | LOW | MITRE-CVE | ||||
| CVSS 3.1 | LOW | [email protected] | ||||
| CVSS 4.0 | LOW | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | LOW | [email protected] |
Solution
- Update Wasmtime to version 48.0.8 or later.
- Update Wasmtime to version 49.0.5 or later.
- Update Wasmtime to version 50.0.1 or later.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-126408.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-126408 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-126408
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-126408 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-126408 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Nov. 13, 2026
Action Type Old Value New Value Added Reference https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3982-jqvv-277m Added SSVC {'id': 'CVE-2026-126408', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-11-13T20:24:29.977618Z'} -
New CVE Received by [email protected]
Nov. 13, 2026
Action Type Old Value New Value Added Description Wasmtime 47.0.0 before 48.0.8, 49.0.0 before 49.0.5, and 50.0.0 before 50.0.1 contains an insufficient type-check in the TypedFunc embedder API for I31, Option<I31>, and Option<NoneRef> parameter or result types, reaching an unreachable!() path. A malicious guest module exporting a function that uses another anyref-hierarchy type can panic the host embedding, causing denial of service. Added CVSS V4.0 AV:A/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:L/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 Added CVSS V3.1 AV:A/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:L Added CWE CWE-617 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/126xxx/CVE-2026-126408.json">CVE-2026-126408</a> Added Reference https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-3982-jqvv-277m Added Reference https://www.vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.8-denial-of-service-via-typedfunc-type-check-panic