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VulnerabilityPublished Updated

CVE-2026-115893: Rust wasmtime · Wasmtime is a runtime for WebAssembly

Affects rust-wasmtimeSource GCVE Database

0
Authoritative record:CVE-2026-115893· Critical 9.9

Not known to be exploited · CVSS 9.9 Critical.

Data as of 28 Oct 2026, 22:42 UTC

CVSS 3.1 base score
9.9Critical
How severe the flaw is on the 0–10 CVSS scale.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 23 Oct 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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

ProductAffectedFixed in
Ubuntu 26.10rust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=stonkingOther threatsAffected
  • =36.0.5+dfsg-1
  • =36.0.13+dfsg-1
Fixed in–
Ubuntu 26.04 LTSrust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=resoluteOther threatsAffected
  • 26.0.1+dfsg-3 – 36.0.5+dfsg-1
5 affected builds
Fixed in–
Ubuntu 24.04 LTSrust-wasmtimepkg:deb/ubuntu/rust-wasmtime?arch=source&distro=nobleOther threatsAffected
  • 10.0.1+dfsg-7 – 16.0.0+dfsg-3
4 affected builds
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Upgrade Wasmtime to version 36.0.19, 48.0.7, or 49.0.4 or later to apply the official fix for this vulnerability. No other mitigations are indicated or required once the fixed versions are deployed.

Description

A critical vulnerability exists in the Cranelift compiler backend of Wasmtime on aarch64 architectures prior to versions 36.0.19, 48.0.7, and 49.0.4. The flaw allows a Wasm br_table instruction with more than approximately 256,000 targets to compile incorrectly, resulting in a conditional branch that can jump to arbitrary code. This enables a user-controlled WebAssembly module to escape the sandbox, potentially leading to full compromise on affected systems. The issue is fixed in the specified versions.

References

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