CVE catalog
CVE-2026-34943
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val
- Severity
- Medium · CVSS 5.6
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:A/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 - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.32% · Oct 25, 2026
Wasmtime is a runtime for WebAssembly. Prior to 24.0.7, 36.0.7, 42.0.2, and 43.0.1, Wasmtime contains a possible panic which can happen when a flags-typed component model value is lifted with the Val type. If bits are set outside of the set of flags the component model specifies that these bits should be ignored but Wasmtime will panic when this value is lifted. This panic only affects wasmtime's implementation of lifting into Val, not when using the flags! macro. This additionally only affects flags-typed values which are part of a WIT interface. This has the risk of being a guest-controlled panic within the host which Wasmtime considers a DoS vector. This vulnerability is fixed in 24.0.7, 36.0.7, 42.0.2, and 43.0.1.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Cpe | wasmtime | Not reported | 24.0.7 | fixed |
| Cpe | wasmtime | Not reported | 36.0.7 | fixed |
| Cpe | wasmtime | Not reported | 42.0.2 | fixed |
| Cpe | wasmtime | Not reported | 43.0.1 | fixed |
| Debian | rust-wasmtime | 13 | 26.0.1+dfsg-10 | vulnerable |
| Debian | rust-wasmtime | 13 | 26.0.1+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 13 | 26.0.1+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 13 | 26.0.1+dfsg-5 | vulnerable |
| Debian | rust-wasmtime | 13 | 26.0.1+dfsg-6 | vulnerable |
| Debian | rust-wasmtime | 13 | 26.0.1+dfsg-7 | vulnerable |
| Debian | rust-wasmtime | 13 | 26.0.1+dfsg-8 | vulnerable |
| Debian | rust-wasmtime | 13 | 26.0.1+dfsg-9 | vulnerable |
| Debian | rust-wasmtime | 13 | 27.0.0+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 13 | 27.0.0+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 13 | 27.0.0+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 13 | 28.0.1+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 28.0.1+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 13 | 28.0.1+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 13 | 29.0.1+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 29.0.1+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 13 | 29.0.1+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 13 | 29.0.1+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 13 | 29.0.1+dfsg-5 | vulnerable |
| Debian | rust-wasmtime | 13 | 29.0.1+dfsg-6 | vulnerable |
| Debian | rust-wasmtime | 13 | 29.0.1+dfsg-7 | vulnerable |
| Debian | rust-wasmtime | 13 | 29.0.1+dfsg-8 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.11+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.12+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.12+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.12+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.13+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.5+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.5+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.5+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.5+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.5+dfsg-5 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.6+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.6+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.6+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.6+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.6+dfsg-5 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.6+dfsg-6 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.6+dfsg-7 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.7+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.8+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.9+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 13 | 36.0.9+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 14 | 26.0.1+dfsg-10 | vulnerable |
| Debian | rust-wasmtime | 14 | 26.0.1+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 14 | 26.0.1+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 14 | 26.0.1+dfsg-5 | vulnerable |
| Debian | rust-wasmtime | 14 | 26.0.1+dfsg-6 | vulnerable |
| Debian | rust-wasmtime | 14 | 26.0.1+dfsg-7 | vulnerable |
| Debian | rust-wasmtime | 14 | 26.0.1+dfsg-8 | vulnerable |
| Debian | rust-wasmtime | 14 | 26.0.1+dfsg-9 | vulnerable |
| Debian | rust-wasmtime | 14 | 27.0.0+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 14 | 27.0.0+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 14 | 27.0.0+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 14 | 28.0.1+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 14 | 28.0.1+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 14 | 28.0.1+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 14 | 29.0.1+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 14 | 29.0.1+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 14 | 29.0.1+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 14 | 29.0.1+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 14 | 29.0.1+dfsg-5 | vulnerable |
| Debian | rust-wasmtime | 14 | 29.0.1+dfsg-6 | vulnerable |
| Debian | rust-wasmtime | 14 | 29.0.1+dfsg-7 | vulnerable |
| Debian | rust-wasmtime | 14 | 29.0.1+dfsg-8 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.5+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.5+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.5+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.5+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.5+dfsg-5 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.6+dfsg-1 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.6+dfsg-2 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.6+dfsg-3 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.6+dfsg-4 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.6+dfsg-5 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.6+dfsg-6 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.6+dfsg-7 | vulnerable |
| Debian | rust-wasmtime | 14 | 36.0.7+dfsg-1 | fixed |
| Cpe | wasmtime | Not reported | 43.0.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Cpe | wasmtime | cpe | Not reported | 24.0.7 | Not reported | Not reported | Not reported |
| Cpe | wasmtime | cpe | Not reported | 36.0.7 | Not reported | Not reported | Not reported |
| Cpe | wasmtime | cpe | Not reported | 42.0.2 | Not reported | Not reported | Not reported |
| Cpe | wasmtime | cpe | Not reported | 43.0.1 | Not reported | Not reported | Not reported |
| Debian | rust-wasmtime | deb | 14 | 36.0.7+dfsg-1 | Not reported | DEBIAN-CVE-2026-34943 | Not reported |
| Cpe | wasmtime | cpe | Not reported | 43.0.1 | Not reported | NVD-CVE-2026-34943 | Not reported |
OpenFactory catalog packages
[Debian 13 (Trixie)]
- [librust-cranelift-dev]Affected
Source package: [rust-wasmtime]
Details (2)
0.113.1+26.0.1+dfsg-3· all · trixieAffected
nvd · rust-wasmtime · debian · 13
0.113.1+26.0.1+dfsg-3· all · trixieAffected
nvd · rust-wasmtime · debian · 13
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_10715-1.json]
- [https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-m758-wjhj-p3jq]
- [https://nvd.nist.gov/vuln/detail/CVE-2026-34943]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2026-34943]
- [https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34943.json]
[FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]