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VulnerabilityPublished Updated

CVE-2026-44216: bytecodealliance wasmtime · Unthrottled Resource Allocation

Affects bytecodealliance wasmtimeSource CVE Database V5

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Not known to be exploited · CVSS 5.9 Medium : upgrade to 43.0.2 or 36.0.8 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 4.0 base score
5.9Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 43.0.2, 36.0.8, 43.0
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

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 14 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

What to do

Upgrade wasmtime to 43.0.2 or 36.0.8; github/bytecodealliance/wasmtime to 43.0 or 36.0.8.

Affected software

ProductAffectedFixed in
bytecodealliancewasmtimeAffected
  • >=30.0.0 <36.0.8
  • >=37.0.0 <43.0.2
  • =44.0.0
Fixed in
  • 43.0.2
  • 36.0.8
crates.iogithub/bytecodealliance/wasmtimepkg:cargo/github/bytecodealliance/wasmtimeOther threatsAffected
  • <36.0.8
  • >=30.0.0 <36.0.8
  • <43.0
  • >=37.0.0 <43.0
  • =44.0.0
Fixed in
  • 36.0.8
  • 43.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The vulnerability is fixed in Wasmtime versions 36.0.8, 43.0.2, and 44.0.1. Users should upgrade to one of these fixed versions to remediate the issue. Red Hat has issued advisories referencing this CVE in Hardened Images RPMs updates; users of Red Hat products should follow Red Hat's update instructions. No alternative mitigations or workarounds are specified in the vendor advisory.

Description

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.

References

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