What is CVE-2026-34043?

CVE-2026-34043 is a medium-severity vulnerability in Yahoo Serialize-javascript, classified under Uncontrolled Resource Consumption. CVSS score: 5.9/10. Published 2026-03-31.

How severe is CVE-2026-34043?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Resource exhaustion in Yahoo Serialize-javascript

CVE-2026-34043

Serialize JavaScript to a superset of JSON that includes regular expressions and functions. Prior to version 7.0.5, there is a Denial of Service (DoS) vulnerability caused by CPU exhaustion. When serializing a specially crafted "array-like…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.000 (5.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Yahoo Serialize-javascript — versions < 7.0.5

Weakness classification (CWE)

References

https://github.com/yahoo/serialize-javascript/security/advisories/GHSA-qj8w-gfj5-8c6v (x_refsource_CONFIRM)
https://github.com/yahoo/serialize-javascript/commit/f147e90269b58bb6e539cfdf3d0e20d6ad14204b (x_refsource_MISC)
https://github.com/yahoo/serialize-javascript/releases/tag/v7.0.5 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-34043?: CVE-2026-34043 is a medium-severity vulnerability in Yahoo Serialize-javascript, classified under Uncontrolled Resource Consumption. CVSS score: 5.9/10. Published 2026-03-31.
How severe is CVE-2026-34043?: Medium severity. CVSS v3 base score is 5.9 out of 10.