GHSA-PM4M-PH32-GHV5 js-yaml: Exponential parsing time in flow collections leads to denial of service

Summary Parsing a small YAML document can take exponential time. An application that calls load or loadAll on untrusted input can be hung by a payload under 200 bytes. Details When an entry in a flow sequence turns out to be a key: value pair, the parser rewinds and parses that entry a second tim...

CVE-2026-59869

A flaw was found in js-yaml, a JavaScript YAML parser and dumper. A remote attacker could exploit this vulnerability by providing a specially crafted YAML document containing a chain of mappings with merge keys. This could cause the parser to consume excessive CPU resources, leading to a Denial o...

CVE-2026-58486 HedgeDoc: Denial-of-service via YAML alias expansion in note frontmatter

HedgeDoc is an open source, real-time, collaborative, markdown notes application. Prior to version 1.11.0, HedgeDoc was vulnerable to a YAML alias bomb due to unsafe processing of the note frontmatter. HedgeDoc parsed frontmatter with js-yaml.load js-yaml v3 via @hedgedoc/meta-marked, which...

js-yaml: js-yaml: Denial of Service via crafted YAML documents

A flaw was found in js-yaml, a JavaScript YAML parser and dumper. A remote attacker could exploit this vulnerability by providing a specially crafted YAML document containing a chain of mappings with merge keys. This could cause the parser to consume excessive CPU resources, leading to a Denial o...

js-yaml: js-yaml: Denial of Service via crafted YAML merge keys

A flaw was found in js-yaml, a JavaScript YAML parser and dumper. A remote attacker can exploit this vulnerability by providing a specially crafted YAML document that repeatedly uses the same alias in a merge sequence. This can lead to algorithmic CPU exhaustion, causing the Node.js worker or eve...

CVE-2026-59870

A flaw was found in js-yaml, a JavaScript YAML YAML Ain't Markup Language parser. An attacker could exploit this by providing a specially crafted YAML ordered-map document. This could lead to excessive CPU consumption, resulting in a denial of service DoS for applications processing the malicious...

Linux Distros Unpatched Vulnerability : CVE-2026-59868

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - 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...

Inefficient Algorithmic Complexity

Overview js-yaml is a human-friendly data serialization language. Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in the merge key handling during YAML parsing, where each mapping in a chain re-enumerates the keys inherited from the previous mapping. An...

Inefficient Algorithmic Complexity

Overview org.webjars.npm:js-yaml is a human-friendly data serialization language. Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in merge key handling during YAML parsing, where each mapping in a chain re-enumerates the keys inherited from the previous...

Inefficient Algorithmic Complexity

Overview js-yaml is a human-friendly data serialization language. Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity in merge key handling during YAML parsing, where each mapping in a chain re-enumerates the keys inherited from the previous mapping. An attacker...

CVE-2026-59870

js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.1, YAML11SCHEMA support for the !!omap tag in src/tag/sequence/omap.ts uses omapTag.addItem to perform a linear duplicate-key scan on every insertion, causing On^2 CPU consumption when yaml.load parses a crafted ordered-map...

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...

UBUNTU-CVE-2026-59870

js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.1, YAML11SCHEMA support for the !!omap tag in src/tag/sequence/omap.ts uses omapTag.addItem to perform a linear duplicate-key scan on every insertion, causing On^2 CPU consumption when yaml.load parses a crafted ordered-map...

CVE-2026-59868

The CVE-2026-59868 Issue: js-yaml (JavaScript YAML parser/dumper) is vulnerable when merge keys are enabled. From versions 5.0.0 up to 5.2.0, a chain of mappings using merge keys can cause quadratic CPU time on documents that grow linearly, leading to DoS under some inputs. A fix was released in ...

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...

CVE-2026-59869 js-yaml: YAML merge-key chains can force quadratic CPU consumption

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...

PT-2026-56491

Name of the Vulnerable Software and Affected Versions js-yaml versions 5.0.0 through 5.2.0 Description Support for the !!omap tag in YAML11 SCHEMA within src/tag/sequence/omap.ts uses the omapTag.addItem function to perform a linear duplicate-key scan during every insertion. This results in On^2...

js-yaml: js-yaml: Denial of Service via crafted YAML ordered-map document

A flaw was found in js-yaml, a JavaScript YAML YAML Ain't Markup Language parser. An attacker could exploit this by providing a specially crafted YAML ordered-map document. This could lead to excessive CPU consumption, resulting in a denial of service DoS for applications processing the malicious...

js-yaml: js-yaml: Denial of Service via crafted YAML ordered-map document

A flaw was found in js-yaml, a JavaScript YAML YAML Ain't Markup Language parser. An attacker could exploit this by providing a specially crafted YAML ordered-map document. This could lead to excessive CPU consumption, resulting in a denial of service DoS for applications processing the malicious...

js-yaml: js-yaml: Denial of Service via crafted YAML merge keys

A flaw was found in js-yaml, a JavaScript YAML parser and dumper. A remote attacker can exploit this vulnerability by providing a specially crafted YAML document that repeatedly uses the same alias in a merge sequence. This can lead to algorithmic CPU exhaustion, causing the Node.js worker or eve...