CVE-2026-58494: Rust wasmtime · Wasmtime is a runtime for WebAssembly
Affects rust-wasmtimeSource GCVE Database
Not known to be exploited · CVSS 6.5 Medium : upgrade to 46.0.1 when convenient.
Data as of 26 Oct 2026, 10:12 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Affects
- rust-wasmtime affecting prior to 24.0.11
- Patch
- Available – fixed in 46.0.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 8 Jul 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
Upgrade wasmtime-wasi to 46.0.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSrust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu 25.10rust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSrust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
| crates.iowasmtime-wasi | Affected
| Fixed in
|
Ubuntu 26.10rust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=stonkingOther 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
A fix is available in rust-wasmtime version 46.0.1. Users should upgrade to this version or later to remediate the vulnerability. No additional vendor advisories indicate alternative mitigations or that the issue is already mitigated.
Description
CVE-2026-58494 is a vulnerability in rust-wasmtime affecting versions prior to 24.0.11, 36.0.12, 45.0.3, and 46.0.1. It allows a WASI guest with read-only source file capability to overwrite host files exposed as read-only due to improper permission checks during hard-link creation and renaming. The issue arises because directory permissions are checked but file permissions on source and destination preopens are not properly matched. The vulnerability is fixed in version 46.0.1.
References
- ubuntu.com/security/CVE-2026-58494 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-58494 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/commit/5ddfd5f1ef28f2041fa07d237ad0336e167b0e0c (opens in a new tab)
- github.com/bytecodealliance/wasmtime/commit/7db94cdcf0c79cb3dfde884b534b653f2dd83367 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/commit/8a250aac0962ca1364b5f16525720e9d0b39edcd (opens in a new tab)
- github.com/bytecodealliance/wasmtime/commit/d3ceb56ec35f39e02496eeb4e2d9c7f4fb964d9e (opens in a new tab)
- github.com/bytecodealliance/wasmtime/releases/tag/v24.0.11 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/releases/tag/v36.0.12 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/releases/tag/v45.0.3 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/releases/tag/v46.0.1 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/security/advisories/GHSA-4ch3-9j33-3pmj (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-58494 (opens in a new tab)
- github.com/bytecodealliance/wasmtime/pull/13725 (opens in a new tab)
- github.com/bytecodealliance/wasmtime (opens in a new tab)
- rustsec.org/advisories/RUSTSEC-2026-0188.html (opens in a new tab)