Skip to main content
No exploitation reportedFix available

CVE-2020-14000

No exploitation reported by the sources we read.

  • Published2020-07-16
  • Fixed in0.2.0-prerelease.20200714185213
  • WeaknessCWE-502

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

MIT Lifelong Kindergarten Scratch scratch-vm before 0.2.0-prerelease.20200714185213 loads extension URLs from untrusted project.json files with certain _ characters, resulting in remote code execution because the URL's content is treated as a script and is executed as a worker. The responsible code is getExtensionIdForOpcode in serialization/sb3.js. The use of _ is incompatible with a protection mechanism in older versions, in which URLs were split and consequently deserialization attacks were prevented. NOTE: the scratch.mit.edu hosted service is not affected because of the lack of worker scripts.

Timeline

dates in UTC
  1. 2020-07-1615:15CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2020-14000?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2020-14000?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Mit scratch-vm
BranchAffectedFixed in
0.2< 0.2.0-prerelease.202007141852130.2.0-prerelease.20200714185213

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update Mit scratch-vm to 0.2.0-prerelease.20200714185213

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.19.8read 2026-10-23
  • NVDCVSS 2.07.5read 2026-10-23
  • NVDweakness (CWE)CWE-502read 2026-10-23
  • FIRST EPSSEPSS score2.8 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published
2020-07-16
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2020-14000?

MIT Lifelong Kindergarten Scratch scratch-vm before 0.2.0-prerelease.20200714185213 loads extension URLs from untrusted project.json files with certain _ characters, resulting in remote code execution because the URL's content is treated as a script and is executed as a worker. The responsible code is getExtensionIdForOpcode in serialization/sb3.js. The use of _ is incompatible with a protection mechanism in older versions, in which URLs were split and consequently deserialization attacks were prevented. NOTE: the scratch.mit.edu hosted service is not affected because of the lack of worker scripts.

Is CVE-2020-14000 actively exploited?

Active exploitation of CVE-2020-14000 has not been confirmed. Its EPSS score was 2.8% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2020-14000?

CVE-2020-14000 has a CVSS v3 base score of 9.8 (CRITICAL severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

Get alerts for this productCISA KEV additions, October 2026Search CVEs

No credit card required · No monthly cap on website lookups · 250 API requests/month

Go further

Related vulnerabilities

Same product first, then the same vendor advisory and the same publication week.

Back to CVE Database