CVE-2026-44216Published

Wasmtime: Panic when allocating a table exceeding the size of the host's address space

Collected exploitation and prediction evidence

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

cve-program · CVE-2026-44216

Published

Wasmtime is a runtime for WebAssembly. From 30.0.0 to 36.0.8, 43.0.2, and 44.0.1, Wasmtime's allocation logic for a WebAssembly table contained checked arithmetic which panicked on overflow. This overflow is possible to trigger, and thus panic, when a table with an extremely large size is allocated. This is possible with the WebAssembly memory64 proposal where tables can have sizes in the 64-bit range as opposed to the previous 32-bit range which would not overflow. The panic happens when attempting to create a very large table, such as when instantiating a WebAssembly module or component. This vulnerability is fixed in 36.0.8, 43.0.2, and 44.0.1.

Source published: 14 May 2026 14:54:32 UTC
Source modified: 28 Jul 2026 12:04:48 UTC
Observed here: 23 Oct 2026 15:48:27 UTC
Source terms: CVE Program Terms of Use

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: cve-program · CVE Program Terms of Use. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · 5.9 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

euvd · EUVD-2026-30304

Published

EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.

Original publisher date fields

datePublished: May 14, 2026, 2:54:32 PM

dateUpdated: Jul 28, 2026, 12:04:48 PM

4 related source bulletins · separate from aliases

openSUSE-SU-2026:10802-1: libtree-sitter0_26-0.26.8-3.1 on GA media

CVE-2026-44216

openSUSE-SU-2026:20863-1: Security update for tree-sitter

CVE-2026-44216

RHSA-2026:45341: Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

CVE-2025-11233 · CVE-2026-44216

SUSE-SU-2026:22002-1: Security update for tree-sitter

CVE-2026-44216

Source published: May 14, 2026, 2:54:32 PM (timezone not stated)
Source modified: Jul 28, 2026, 12:04:48 PM (timezone not stated)
Observed here: 28 Oct 2026 06:06:33 UTC
Source terms: ENISA EUVD · source terms and attribution apply

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: euvd · ENISA EUVD · source terms and attribution apply. Source text is retained; field grouping and change labels are provided by ChangeIntel.

EUVD CVSS 4.0 · 5.9 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

nvd · CVE-2026-44216

Published

NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.

Source analysis status: Modified

Weakness classifications: CWE-770 · CWE-190

Original publisher date fields

published: 2026-05-14T15:16:47.793

lastModified: 2026-10-26T14:10:00.130

2 source CPE criteria · context only

cpe:2.3:a:bytecodealliance:wasmtime:*:*:*:*:*:rust:*:*
cpe:2.3:a:bytecodealliance:wasmtime:44.0.0:*:*:*:*:rust:*:*

The original JSON retains the logical configuration operators, exclusions and version bounds.

Source published: 14 May 2026 15:16:47 UTC
Source modified: 26 Oct 2026 14:10:00 UTC
Observed here: 27 Oct 2026 11:12:09 UTC
Source terms: NIST NVD usage terms; underlying source attribution retained

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 5.9 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 · [email protected] · Primary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

osv · GHSA-p8xm-42r7-89xg

Published

### Impact Wasmtime's allocation logic for a WebAssembly table contained checked arithmetic which panicked on overflow. This overflow is possible to trigger, and thus panic, when a table with an extremely large size is allocated. This is possible with the WebAssembly memory64 proposal where tables can have sizes in the 64-bit range as opposed to the previous 32-bit range which would not overflow. The panic happens when attempting to create a very large table, such as when instantiating a WebAssembly module or component. This bug does not affect the pooling allocator which limits tables sizes to much less than the required amount to trigger the overflow. This bug is only present for the on-demand instance allocator, which is Wasmtime's default allocator. This bug also requires the `memory64` WebAssembly feature to be enabled, which is on-by-default. Panicking in the host process is considered a denial-of-service vector for Wasmtime. ### Patches Wasmtime 36.0.8, 43.0.2, and 44.0.1 have all been released which fixes this issue. ### Workarounds Embeddings can switch to using the pooling allocator to work around this issue, or the `memory64` WebAssembly proposal can be disabled. Otherwise there is no workaround and users are recommended to upgrade.

Source published: 7 May 2026 00:08:59 UTC
Source modified: 10 Sep 2026 03:51:06 UTC
Observed here: 24 Oct 2026 13:19:54 UTC
Source terms: GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · 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

Publisher rating · MODERATE

osv · RUSTSEC-2026-0114

Published

This is an entry in the RustSec database for the Wasmtime security advisory located at https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-p8xm-42r7-89xg For more information see the GitHub-hosted security advisory.

Source published: 30 Apr 2026 12:00:00 UTC
Source modified: 12 Oct 2026 18:00:08 UTC
Observed here: 24 Oct 2026 13:19:54 UTC
Source terms: OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · 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