What is CVE-2021-26194?

CVE-2021-26194 is a medium-severity vulnerability in Jerryscript, classified under Use After Free. CVSS score: 6.5/10. Published 2021-06-10.

How severe is CVE-2021-26194?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Use After Free in Jerryscript

CVE-2021-26194

An issue was discovered in JerryScript 2.4.0. There is a heap-use-after-free in ecma_is_lexical_environment in the ecma-helpers.c file.

Vulnerability class: Use-After-Free

Published 2021-06-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.009 (59.6th percentile), scored 2026-10-07.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 60th percentile — 59.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Jerryscript — versions 2.4.0

Weakness classification (CWE)

CWE-416 — Use After Free

References

github.com/jerryscript-project/jerryscript/issues/4445 (Exploit, Patch, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-26194?: CVE-2021-26194 is a medium-severity vulnerability in Jerryscript, classified under Use After Free. CVSS score: 6.5/10. Published 2021-06-10.
How severe is CVE-2021-26194?: Medium severity. CVSS v3 base score is 6.5 out of 10.