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CVE-2026-118688VulnerabilityPublished

Wasmtime-wasi

Affects wasmtime-wasiSource GCVE Database

0
Authoritative record:CVE-2026-118688· High 8.8

Not known to be exploited · CVSS 8.8 High · fixed in 49.0.3 : patch wasmtime-wasi soon.

Data as of 28 Oct 2026, 22:14 UTC

CVSS 4.0 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
Affects
Wasmtime before 36.0.18
Patch
Available – fixed in 49.0.3, 48.0.6, 36.0.18
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 28 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

Upgrade bytecodealliance/wasmtime-wasi to 49.0.3, 48.0.6 or 36.0.18.

Affected software

ProductAffectedFixed in
crates.iobytecodealliance/wasmtime-wasipkg:cargo/bytecodealliance/wasmtime-wasiOther threatsAffected
  • <36.0.18
  • >=37.0.0 <48.0.6
  • >=49.0.0 <49.0.3
Fixed in
  • 36.0.18
  • 48.0.6
  • 49.0.3

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

AI-suggested

The vulnerability affects specific Wasmtime versions before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3. Users should upgrade to versions 36.0.18 or later, 48.0.6 or later, and 49.0.3 or later respectively to mitigate this issue. No vendor advisory or patch links were provided, so confirm patch availability from official Wasmtime sources before applying updates.

Description

A vulnerability in wasmtime-wasi in Wasmtime versions before 36.0.18, 37.0.0 before 48.0.6, and 49.0.0 before 49.0.3 causes a trailing slash to be re-appended to rename source paths. This behavior leads to the renameat system call on macOS and FreeBSD hosts following directory symbolic links. Consequently, a guest with sandbox write access can rename a relative symlink such as "up/" to move host directories into its sandbox, enabling unauthorized read or write access to those directories.

References

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