Rust wasmtime: Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability
Affects rust-wasmtimeSource GCVE Database
Not known to be exploited · CVSS 5.9 Medium.
Data as of 28 Oct 2026, 22:31 UTC
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10rust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSrust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSrust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
Wasmtime 47.0.0 before 48.0.4 and 49.0.0 before 49.0.2 contains an improper validation vulnerability that accepts components whose core modules import WebAssembly tags with a subtype of the original type. Malicious guests can mis-type exception object payloads to corrupt the GC heap, causing Wasmtime to panic when the exceptions proposal is enabled.
References
- ubuntu.com/security/CVE-2026-115383 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-115383 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-cfhf-m2cr-62wj (opens in a new tab)
- vulncheck.com/advisories/wasmtime-47.0.0-before-48.0.4-and-49.0.0-before-49.0.2-gc-heap-corruption-via-tag-imports (opens in a new tab)