MEDIUM

CVE-2026-59868

CVSS v3

5.3

MEDIUM

EPSS Score

0.6 %

exploit probability, as of 2026-10-17

CISA KEV

known exploited

Exploitation

—

SSVC status

Get an alert for each new CVE published for js-yaml. Watch js-yaml in CVE Watch Free account · no credit card

Affected and fixed versions

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

js-yamlnpmfrom 5.0.0 · fixed in 5.2.0

Vendor advisories

CVE-2026-59868 Red Hat Product Security138 products fixed
js-yaml: js-yaml: Denial of Service via quadratic CPU time parsing with merge keys
RHSA-2026:61783 Red Hat Product Security2 products fixed
Red Hat Security Advisory: A Subscription Management tool for finding and reporting Red Hat product usage
RHSA-2026:35272 Red Hat Product Security17 products fixed
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
RHSA-2026:34975 Red Hat Product Security39 products fixed
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
RHSA-2026:34478 Red Hat Product Security17 products fixed
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update
RHSA-2026:33866 Red Hat Product Security17 products fixed
Red Hat Security Advisory: Red Hat Hardened Images RPMs Security Update

4 more advisories

Full record on NVD

Description

js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.0, when merge keys are enabled, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in version 5.2.0.

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Published: 2026-07-08
Last Modified: 2026-07-08
GitHub Advisory: GHSA-g796-fgmg-93mv

Frequently asked questions

What is CVE-2026-59868?

Is CVE-2026-59868 actively exploited?

Active exploitation of CVE-2026-59868 has not been confirmed. Its EPSS score was 0.6% on 2026-10-17, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-59868?

CVE-2026-59868 has a CVSS v3 base score of 5.3 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

Running js-yaml? Hear about its next vulnerability

CVE Watch matches each new CVE to the vendors and products you list (vendor and product, not the version) and puts it in your alerts with its KEV and EPSS status.

Get alerts for this product CISA KEV additions, October 2026 Search CVEs

Already have an account? Open CVE WatchNo credit card required · 50 free checks/month · Free API key

Go further

Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
Running this software? CVE Watch alerts you to new vulnerabilities in your products.

Related vulnerabilities

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

Back to CVE Database