Vulnerability · CVE-2026-25641
SandboxJS is a JavaScript sandboxing library.
Published Feb 6, 2026 · catalog updated Feb 6, 2026 · SandboxJS is a JavaScript
Last checked Nov 4, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-25641. EPSS is 0.52%. Act only if a listed version of SandboxJS is a JavaScript is installed.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (SandboxJS is a JavaScript).
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2026-43898 · Critical
- CVE-2026-34217 · Medium
- CVE-2026-34211 · Medium
- CVE-2026-34208 · Critical
- CVE-2026-32723 · Medium
- Severity
- Critical10.0
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.52%
- Remediation
- Version ranges on file
- Affected products
- vendor nyariv sandboxjs < 0.8.29
SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, there is a sandbox escape vulnerability due to a mismatch between the key on which the validation is performed and the key used for accessing properties. Even though the key used in property accesses is annotated as string, this is never enforced. So, attackers can pass malicious objects that coerce to different string values when used, e.g., one for the time the key is sanitized using hasOwnProperty(key) and a different one for when the key is used for the actual property access. This vulnerability is fixed in 0.8.29.
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor nyariv sandboxjs < 0.8.29< 0.8.29
How to fix CVE-2026-25641
Upgrade
CVE-2026-25641 lists a fix boundary at 0.8.29. Compare the installed build with that boundary before you change production.
Version check
Affected < 0.8.29
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-25641. EPSS is 0.52%. Act only if a listed version of SandboxJS is a JavaScript is installed.
Which versions are affected?
Compare what you have installed with nyariv sandboxjs < 0.8.29 < 0.8.29. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.52%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Feb 6, 2026 · EUVD
Detected
SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, there is a sandbox escape vulnerability due to a mismatch between the key on which the validation is performed and the key used for accessing properties. Even though the key used in property accesses is annotated as string, this is never enforced. So, attackers can pass malicious objects that coerce to different string values when used
Feb 6, 2026 · EUVD
Updated
SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, there is a sandbox escape vulnerability due to a mismatch between the key on which the validation is performed and the key used for accessing properties. Even though the key used in property accesses is annotated as string, this is never enforced. So, attackers can pass malicious objects that coerce to different string values when used
Sources
- CVE.orgVulnerability recordCVE-2026-25641
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-25641
30-day exploitation probability 0.52%
first.org - EUVDVulnerability recordEUVD-2026-5589
SandboxJS is a JavaScript sandboxing library. Prior to 0.8.29, there is a sandbox escape vulnerability due to a mismatch between the key on which the validation is performed and the key used for accessing properties. Even though the key used in property accesses is annotated as s
euvd.enisa.europa.eu
References
Freshness
Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- FIRST EPSSNov 4, 2026
- CVE.orgNov 4, 2026
- EUVDNov 3, 2026