Is there a public exploit for CVE-2026-84375?

No public exploit for CVE-2026-84375 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-84375?

CVE-2026-84375 scores CVSS 7.5 (v3.1), rated high. EPSS puts the chance of exploitation in the next 30 days at 0.54%.

What does CVE-2026-84375 affect?

CVE-2026-84375 affects nodeca js-yaml.

7.5 High

js-yaml is a JavaScript YAML parser and dumper.

CVE-2026-84375

js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 until 3.15.2, 4.3.2, and 5.4.1, maxTotalMergeKeys in lib/js-yaml/loader.js and lib/loader.js does not count empty mapping sources while processing the merge key <<. An attacker can alias a large sequence of empty mappings into many merge targets, causing O(N K) processing while totalMergeKeys remains unchanged and the configured resource limit is never reached. A relatively small YAML document can therefore cause prolonged CPU consumption in applications that parse untrusted YAML, and merge processing is enabled by default on these release lines. In v3 & v4, merge is enabled by default so the severity score is higher. This issue is fixed in versions 3.15.2, 4.3.2, and 5.4.1.

Assessment

CVSS: 7.5 (v3.1)
Severity: High
EPSS: 0.54% chance of exploitation in the next 30 days
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 1 September 2026
Last updated: 28 September 2026
Affected: nodeca · js-yaml
Weakness: CWE-400, CWE-407
Assigner: security-advisories@github.com

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

At the source

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