CVE catalog

CVE-2026-27601

Severity: High · CVSS 8.2
Published: Mar 3, 2026, 5:46:06 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.96% · Oct 25, 2026

Underscore.js is a utility-belt library for JavaScript. Prior to 1.13.8, the _.flatten and _.isEqual functions use recursion without a depth limit. Under very specific conditions, detailed below, an attacker could exploit this in a Denial of Service (DoS) attack by triggering a stack overflow. Untrusted input must be used to create a recursive datastructure, for example using JSON.parse, with no enforced depth limit. The datastructure thus created must be passed to _.flatten or _.isEqual. In the case of _.flatten, the vulnerability can only be exploited if it is possible for a remote client to prepare a datastructure that consists of arrays at all levels AND if no finite depth limit is passed as the second argument to _.flatten. In the case of _.isEqual, the vulnerability can only be exploited if there exists a code path in which two distinct datastructures that were submitted by the same remote client are compared using _.isEqual. For example, if a client submits data that are stored in a database, and the same client can later submit another datastructure that is then compared to the data that were saved in the database previously, OR if a client submits a single request, but its data are parsed twice, creating two non-identical but equivalent datastructures that are then compared. Exceptions originating from the call to _.flatten or _.isEqual, as a result of a stack overflow, are not being caught. This vulnerability is fixed in 1.13.8.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	underscore	sid	`1.13.8~dfsg+~1.13.0-1`	fixed
Debian	underscore	forky	`1.13.8~dfsg+~1.13.0-1`	fixed
Debian	underscore	trixie	`1.13.4~dfsg+~1.11.4-3`	vulnerable
Debian	underscore	bookworm	`1.13.4~dfsg+~1.11.4-3`	vulnerable
Npm	underscore	Not reported	`1.13.8`	fixed
Cpe	underscore	Not reported	Not reported	vulnerable
Npm	underscore	Not reported	`1.13.8`	fixed
Ubuntu	ruby-rails-assets-underscore	18.04	`1.8.3+dfsg-1`	vulnerable
Ubuntu	ruby-rails-assets-underscore	20.04	`1.8.3+dfsg-1`	vulnerable
Ubuntu	ruby-rails-assets-underscore	22.04	`1.8.3+dfsg-4`	vulnerable
Ubuntu	ruby-rails-assets-underscore	24.04	`1.8.3+dfsg-4`	vulnerable
Ubuntu	ruby-rails-assets-underscore	24.04	`1.8.3+dfsg-5`	vulnerable
Opensuse	python-nbclassic	tumbleweed	`1.3.3-1.1`	fixed
Opensuse	python-ipympl	tumbleweed	`0.9.7-17.1`	fixed

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	underscore	source	sid	`1.13.8~dfsg+~1.13.0-1`	not yet assigned	Not reported	Not reported
Debian	underscore	source	forky	`1.13.8~dfsg+~1.13.0-1`	not yet assigned	Not reported	Not reported
Debian	underscore	source	trixie	`(unfixed)`	not yet assigned	Not reported	Not reported
Debian	underscore	source	bookworm	`(unfixed)`	not yet assigned	Not reported	Not reported
Npm	underscore	npm	Not reported	`1.13.8`	Not reported	GHSA-QPX9-HPMF-5GMW	Not reported
Npm	underscore	npm	Not reported	`1.13.8`	Not reported	Not reported	Not reported
Opensuse	python-nbclassic	rpm	tumbleweed	`1.3.3-1.1`	Not reported	OPENSUSE-SU-2026:10440-1	Not reported
Opensuse	python-ipympl	rpm	tumbleweed	`0.9.7-17.1`	Not reported	OPENSUSE-SU-2026:10427-1	Not reported

Notes

[trixie] underscore: Minor issue [bookworm] underscore: Minor issue

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libjs-underscore]Affected
Source package: [underscore]
Details (2)
- 1.13.4~dfsg+~1.11.4-3 · all · bookworm
  Affected
  nvd · underscore · debian · bookworm; nvd · underscore · debian · 12
- 1.13.4~dfsg+~1.11.4-3 · all · bookworm
  Affected
  nvd · underscore · debian · bookworm; nvd · underscore · debian · 12
[node-underscore]Affected
Source package: [underscore]
Details (2)
- 1.13.4~dfsg+~1.11.4-3 · all · bookworm
  Affected
  nvd · underscore · debian · bookworm; nvd · underscore · debian · 12
- 1.13.4~dfsg+~1.11.4-3 · all · bookworm
  Affected
  nvd · underscore · debian · bookworm; nvd · underscore · debian · 12

[Debian 13 (Trixie)]

[libjs-underscore]Affected
Source package: [underscore]
Details (2)
- 1.13.4~dfsg+~1.11.4-3 · all · trixie
  Affected
  nvd · underscore · debian · 13
- 1.13.4~dfsg+~1.11.4-3 · all · trixie
  Affected
  nvd · underscore · debian · 13
[node-underscore]Affected
Source package: [underscore]
Details (2)
- 1.13.4~dfsg+~1.11.4-3 · all · trixie
  Affected
  nvd · underscore · debian · 13
- 1.13.4~dfsg+~1.11.4-3 · all · trixie
  Affected
  nvd · underscore · debian · 13

[openSUSE Tumbleweed]

[jupyter-matplotlib]Unknown
Source package: [python-ipympl]
Details (1)
- 0.11.7-18.1 · noarch · tumbleweed
  Unknown · Fixed: 0.9.7-17.1
  Version impact unknown
  nvd · python-ipympl · opensuse · tumbleweed
[jupyter-matplotlib-jupyterlab]Unknown
Source package: [python-ipympl]
Details (1)
- 0.11.7-18.1 · noarch · tumbleweed
  Unknown · Fixed: 0.9.7-17.1
  Version impact unknown
  nvd · python-ipympl · opensuse · tumbleweed
[jupyter-nbclassic]Unknown
Source package: [python-nbclassic]
Details (1)
- 1.3.3-2.3 · noarch · tumbleweed
  Unknown · Fixed: 1.3.3-1.1
  Version impact unknown
  nvd · python-nbclassic · opensuse · tumbleweed
[python313-ipympl]Unknown
Source package: [python-ipympl]
Details (1)
- 0.10.0-18.1 · noarch · tumbleweed
  Unknown · Fixed: 0.9.7-17.1
  Version impact unknown
  nvd · python-ipympl · opensuse · tumbleweed
[python313-nbclassic]Unknown
Source package: [python-nbclassic]
Details (1)
- 1.3.3-2.3 · noarch · tumbleweed
  Unknown · Fixed: 1.3.3-1.1
  Version impact unknown
  nvd · python-nbclassic · opensuse · tumbleweed
[python314-ipympl]Unknown
Source package: [python-ipympl]
Details (1)
- 0.10.0-18.1 · noarch · tumbleweed
  Unknown · Fixed: 0.9.7-17.1
  Version impact unknown
  nvd · python-ipympl · opensuse · tumbleweed
[python314-nbclassic]Unknown
Source package: [python-nbclassic]
Details (1)
- 1.3.3-2.3 · noarch · tumbleweed
  Unknown · Fixed: 1.3.3-1.1
  Version impact unknown
  nvd · python-nbclassic · opensuse · tumbleweed

Observed: Oct 24, 2026, 12:38:13 AM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]