How severe is CVE-2026-59869?

CVE-2026-59869 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2026-59869 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-59869?

CVE-2026-59869 affects Nodeca Js-yaml. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-59869?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-59869 published?

CVE-2026-59869 was published on 2026-07-08 and last updated on 2026-07-13.

CVE-2026-59869

CVE-2026-59869 is a high-severity vulnerability in Nodeca Js-yaml with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-407.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 1% (43rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-407
Affected product: Nodeca Js-yaml
Published: 2026-07-08
Last modified: 2026-07-13

Description

js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, 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 versions 3.15.0 and 4.3.0.

Frequently asked questions

What is CVE-2026-59869?: js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, 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 versions 3.15.0 and 4.3.0.
How severe is CVE-2026-59869?: CVE-2026-59869 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-59869 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (43rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-59869?: CVE-2026-59869 affects Nodeca Js-yaml. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-59869?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-59869 published?: CVE-2026-59869 was published on 2026-07-08 and last updated on 2026-07-13.

References

Affected products (1)

cpe:2.3:a:nodeca:js-yaml:*:*:*:*:*:node.js:*:*

More vulnerabilities in Nodeca Js-yaml

CVE-2013-4660 — Medium (CVSS 6.8): The JS-YAML module before 2.0.5 for Node.js parses input without properly considering the unsafe !!js/function tag,…
CVE-2026-59870 — Medium (CVSS 5.3): js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.1, YAML11_SCHEMA support for the !!omap tag in…
CVE-2026-59868 — Medium (CVSS 5.3): 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…
CVE-2026-53550 — Medium (CVSS 5.3): js-yaml is a JavaScript YAML parser and dumper. Prior to 4.2.0 and 3.15.0, a crafted YAML document can trigger…
CVE-2025-64718 — Medium (CVSS 5.3): js-yaml is a JavaScript YAML parser and dumper. In js-yaml before 4.1.1 and 3.14.2, it's possible for an attacker to…

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Other CWE-407 vulnerabilities

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CVE-2026-58059 — High (CVSS 8.7): In Bouncy Castle for Java before 1.85, Quadratic-time escaping when stringifying X.500 distinguished names. This issue…
CVE-2026-65623 — High (CVSS 8.7): Inefficient Algorithmic Complexity vulnerability in mtrudel bandit allows unauthenticated remote denial of service via…
CVE-2026-57480 — High (CVSS 8.7): Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to…
CVE-2026-55206 — High (CVSS 8.7): py7zr is a Python-based library and utility to support 7zip archive compression, decompression, encryption and…

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