CVE-2026-115892: bytecodealliance wasmtime · Type Confusion
Affects bytecodealliance wasmtimeSource CVE Database V5
Not known to be exploited · CVSS 5.7 Medium : upgrade to 49.0.4 or 48.0.7 when convenient.
Data as of 29 Oct 2026, 19:15 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 4.0 | 5.7 |
|---|
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 37% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 49.0.4, 48.0.7
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation 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 49.0.4 or 48.0.7.
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
This vulnerability is fixed in Wasmtime versions 48.0.7 and 49.0.4. Users should upgrade to at least these versions to remediate the issue. No additional mitigation steps are indicated by the vendor advisory.
Description
Wasmtime is a runtime for WebAssembly. From 46.0.0 until 48.0.7 and 49.0.4, lowering a host-created component-model stream or future into a guest can omit a required payload-type check after the value passes through guest code and returns through StreamAny, FutureAny, Val::Stream, Val::Future, or an equivalent typed reader. A malicious guest that controls exported function types or returned values can cause the host to pass the type-erased value to a guest expecting a different payload type, which panics the Wasmtime host. This issue is fixed in versions 48.0.7 and 49.0.4.
References
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-9pvw-hwfg-92h5 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/pull/14819 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/pull/14820 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/pull/14827 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/commit/222ff3a65dab9aa7011f8c246937751a0bac5abd (opens in a new tab)
- github.com/bytecodealliance/wasmtime/commit/48dacc76241f06088e79f3ce1b17642f2f7bf158 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/commit/994549891c8a706cb4f2809f9d17b9f67b31e618 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/releases/tag/v48.0.7 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/releases/tag/v49.0.4 (opens in a new tab)