Quick answers
- Is CVE-2026-25142 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-25142 being exploited in the wild.
- How severe is CVE-2026-25142?
- Low severity, with a CVSS score of 3.1, published 2 February 2026.
- Which products and versions are affected?
- @nyariv/sandboxjs (npm) SEMVER:introduced=0,fixed=0.8.27; Nyariv Sandboxjs <= 0.8.26.
- Is there a fix for CVE-2026-25142?
- Yes. @nyariv/sandboxjs (npm): upgrade to 0.8.27 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-25142 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-25142?
- Check whether you run @nyariv/sandboxjs (npm) or Nyariv Sandboxjs at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- @nyariv/sandboxjs (npm): upgrade to 0.8.27 or later
npm install @nyariv/sandboxjs@0.8.27
Technical details
SandboxJS fails to properly restrict access to the __lookupGetter__ method, which can be used to obtain Object prototypes and bypass sandbox isolation. The vulnerability exists in the function property access code path (executor.ts lines 368-398), where a special case for functions bypasses prototype chain whitelist checks that normally protect the root Object prototype. An unauthenticated attacker can inject a payload that uses __lookupGetter__ to access the forbidden __proto__ property, allowing them to escape the sandbox and execute arbitrary Node.js code via child_process.execSync(). The fix is available in version 0.8.27; all versions prior to 0.8.26 are affected.
Affected products
- nyariv SandboxJS <= 0.8.26
Identifiers
- CVE-2026-25142
- GHSA-9p4w-fq8m-2hp7
Timeline
- 2026-02-02: disclosed: GHSA-9p4w-fq8m-2hp7 and CVE-2026-25142 published
- 2026-02-02: patched: Fix released in version 0.8.27