Cranelift compiler causes silent overflow · Wasmtime: Bit-packing
Affects MicrosoftSource GCVE Database
Not known to be exploited · CVSS 9.9 Critical : upgrade to 43.0.0 or 36.0.19 as a priority.
Data as of 29 Oct 2026, 10:37 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 9.9 |
|---|
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 43.0.0, 36.0.19
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by 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 29 Oct 2026.
What to do
Upgrade wasmtime and bytecodealliance/wasmtime to 43.0.0 or 36.0.19.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| bytecodealliancewasmtime | Affected
| Fixed in
|
| bytecodealliancewasmtime | Affected
| Fixed in
|
GitHubbytecodealliance/wasmtimepkg:github/bytecodealliance/wasmtimeOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
No specific mitigation steps are detailed in the available data.
Description
A vulnerability in Wasmtime's Cranelift compiler causes silent overflow and miscompilation due to bit-packing issues. This flaw can lead to incorrect program behavior without explicit errors or warnings.