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VulnerabilityPublished

CVE-2026-59870: Node js yaml · js-yaml is a JavaScript YAML parser and dumper

Affects node-js-yamlSource GCVE Database

0
Authoritative record:CVE-2026-59870· High 7.5

Not known to be exploited · CVSS 7.5 High · fixed in 5.2.1 : patch node-js-yaml soon.

Data as of 26 Oct 2026, 11:42 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.7% chance of exploitation in 30 days – higher than 54% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Affects
js-yaml prior to 5.2.1
Patch
Available – fixed in 5.2.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 8 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Affected software

ProductAffectedFixed in
Ubuntu 26.10node-js-yamlpkg:deb/ubuntu/node-js-yaml?arch=source&distro=stonkingOther threatsAffected
  • =4.1.1+dfsg+~4.0.9-1
  • =4.2.0+~4.0.9-1
  • =4.2.0+~4.0.9-2
Fixed in–
Ubuntu 26.04 LTSnode-js-yamlpkg:deb/ubuntu/node-js-yaml?arch=source&distro=resoluteOther threatsAffected
  • =4.1.0+dfsg+~4.0.5-7
  • =4.1.1+dfsg+~4.0.9-1
Fixed in–
Ubuntu 25.10node-js-yamlpkg:deb/ubuntu/node-js-yaml?arch=source&distro=questingOther threatsAffected
  • =4.1.0+dfsg+~4.0.5-7
Fixed in–
Ubuntu 24.04 LTSnode-js-yamlpkg:deb/ubuntu/node-js-yaml?arch=source&distro=nobleOther threatsAffected
  • =4.1.0+dfsg+~4.0.5-7
Fixed in–
Ubuntu 22.04 LTSnode-js-yamlpkg:deb/ubuntu/node-js-yaml?arch=source&distro=jammyOther threatsAffected
  • 3.14.1+dfsg+~3.12.6-2 – 4.1.0+dfsg+~4.0.5-6
4 affected builds
Fixed in–
Ubuntu 20.04 LTSnode-js-yamlpkg:deb/ubuntu/node-js-yaml?arch=source&distro=focalOther threatsAffected
  • =3.13.1+dfsg-2
Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix for this vulnerability is available in js-yaml version 5.2.1. Users should upgrade to version 5.2.1 or later to remediate this issue.

Description

CVE-2026-59870 is a medium-severity vulnerability in the js-yaml library used by nodeca. It results in excessive CPU consumption due to inefficient quadratic time complexity when processing the !!omap tag in YAML documents. This can cause denial of service by exhausting CPU resources. The vulnerability affects multiple versions of js-yaml prior to 5.2.1. A fix is available in version 5.2.1.

References

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