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Fencer Vulns
high 7.5

CVE-2026-44216 json

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

published 2026-04-30 6 mo ago modified 2026-10-26 14 d ago also EUVD-2026-30304 , GHSA-p8xm-42r7-89xg , JLSEC-2026-1365 , RUSTSEC-2026-0114

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

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.

Patch / fix

  • crates.io wasmtime 36.0.8, 43.0.2, 44.0.1
  • julia Wasmtime_jll 45.0.1+0
  • Red Hat Red Hat Hardened Images 1.97.1-2.hum1
  • rust-wasmtime Debian 14 36.0.8+dfsg-1

debian advisories DEBIAN-CVE-2026-44216

  • rust hummingbird 1 1.97.1-2.hum1
  • cargo hummingbird 1 1.97.1-2.hum1
  • clippy hummingbird 1 1.97.1-2.hum1
  • rustfmt hummingbird 1 1.97.1-2.hum1
  • rust-gdb hummingbird 1 1.97.1-2.hum1
  • rust-src hummingbird 1 1.97.1-2.hum1
  • rust-lldb hummingbird 1 1.97.1-2.hum1
  • rust-analyzer hummingbird 1 1.97.1-2.hum1

red hat advisories RHSA-2026:45341

  • tree-sitter SLES for SAP applications 16.0, SLES 16.0 0.26.8-160000.2.1

suse advisories SUSE-SU-2026:22002-1

  • tree-sitter openSUSE Tumbleweed 0.26.8-3.1

opensuse advisories openSUSE-SU-2026:10802-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-44216 updated cvss 7.5

wasmtime: Wasmtime: Denial of Service via large WebAssembly table allocation

  • Red Hat Hardened Images rust 1.97.1-2.hum1, cargo 1.97.1-2.hum1, clippy 1.97.1-2.hum1, rustfmt 1.97.1-2.hum1, rust-gdb 1.97.1-2.hum1, rust-src 1.97.1-2.hum1, +11 more
    fixed: vendor fix RHSA-2026:45341
  • Red Hat Enterprise Linux 10 virt-firmware-rs
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 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
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 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/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
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
crates.io wasmtime
>=30.0.0, <36.0.8
>=37.0.0, <43.0.2
>=44.0.0, <44.0.1
36.0.8
43.0.2
44.0.1
julia Wasmtime_jll
>=39.0.0+0, <45.0.1+0
45.0.1+0

Affected products

  • bytecodealliance wasmtime
  • Red Hat Red Hat Hardened Images
  • Red Hat Red Hat Enterprise Linux 10

Classification

Weakness
  • CWE-770 Allocation of Resources Without Limits or Throttling
  • CWE-190 Integer Overflow or Wraparound

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.