UnratedFix available

DEBIAN-CVE-2026-27601

Type: advisorySource: OSV1 source record

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.

Announced 3 Mar 2026Group revision 1

Original source ↗

DEBIAN-CVE-2026-27601

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:DEBIAN-CVE-2026-27601

underscore

Source reference: /affected/0/package/name

Affected versions: 1.13.4~dfsg+~1.11.4-3
Source reference: /affected/0/versions
1.13.7~dfsg+~1.13.0-1
Source reference: /affected/0/versions
1.13.7~dfsg+~1.13.0-2
Source reference: /affected/0/versions
1.13.7~dfsg+~1.13.0-3
Source reference: /affected/0/versions
1.13.7~dfsg+~1.13.0-4
Source reference: /affected/0/versions
1.13.7~dfsg+~1.13.0-5
Source reference: /affected/0/versions
1.13.7~dfsg+~1.13.0-6
Source reference: /affected/0/versions
1.13.8~dfsg+~1.13.0-1
Source reference: /affected/0/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

underscore

Source reference: /affected/1/package/name

Affected versions: 1.13.4~dfsg+~1.11.4-3
Source reference: /affected/1/versions
1.13.7~dfsg+~1.13.0-1
Source reference: /affected/1/versions
1.13.7~dfsg+~1.13.0-2
Source reference: /affected/1/versions
1.13.7~dfsg+~1.13.0-3
Source reference: /affected/1/versions
1.13.7~dfsg+~1.13.0-4
Source reference: /affected/1/versions
1.13.7~dfsg+~1.13.0-5
Source reference: /affected/1/versions
1.13.7~dfsg+~1.13.0-6
Source reference: /affected/1/versions
1.13.8~dfsg+~1.13.0-1
Source reference: /affected/1/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

underscore

Source reference: /affected/2/package/name

Affected versions: 1.13.4~dfsg+~1.11.4-3
Source reference: /affected/2/versions
1.13.7~dfsg+~1.13.0-1
Source reference: /affected/2/versions
1.13.7~dfsg+~1.13.0-2
Source reference: /affected/2/versions
1.13.7~dfsg+~1.13.0-3
Source reference: /affected/2/versions
1.13.7~dfsg+~1.13.0-4
Source reference: /affected/2/versions
1.13.7~dfsg+~1.13.0-5
Source reference: /affected/2/versions
1.13.7~dfsg+~1.13.0-6
Source reference: /affected/2/versions
Fixed versions: 1.13.8~dfsg+~1.13.0-1
Source reference: /affected/2/ranges
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "underscore",
      "purl": "pkg:deb/debian/underscore?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "1.13.4~dfsg+~1.11.4-3",
      "1.13.7~dfsg+~1.13.0-1",
      "1.13.7~dfsg+~1.13.0-2",
      "1.13.7~dfsg+~1.13.0-3",
      "1.13.7~dfsg+~1.13.0-4",
      "1.13.7~dfsg+~1.13.0-5",
      "1.13.7~dfsg+~1.13.0-6",
      "1.13.8~dfsg+~1.13.0-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27601.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "underscore",
      "purl": "pkg:deb/debian/underscore?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "1.13.4~dfsg+~1.11.4-3",
      "1.13.7~dfsg+~1.13.0-1",
      "1.13.7~dfsg+~1.13.0-2",
      "1.13.7~dfsg+~1.13.0-3",
      "1.13.7~dfsg+~1.13.0-4",
      "1.13.7~dfsg+~1.13.0-5",
      "1.13.7~dfsg+~1.13.0-6",
      "1.13.8~dfsg+~1.13.0-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27601.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.13.8~dfsg+~1.13.0-1"
          }
        ]
      }
    ],
    "package": {
      "name": "underscore",
      "purl": "pkg:deb/debian/underscore?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "1.13.4~dfsg+~1.11.4-3",
      "1.13.7~dfsg+~1.13.0-1",
      "1.13.7~dfsg+~1.13.0-2",
      "1.13.7~dfsg+~1.13.0-3",
      "1.13.7~dfsg+~1.13.0-4",
      "1.13.7~dfsg+~1.13.0-5",
      "1.13.7~dfsg+~1.13.0-6"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-27601.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event: #56712 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 16:47:19 GMT
Publisher date: Tue, 03 Mar 2026 23:15:55 GMT

Read the original announcement

Revision history

25 Oct 2026DEBIAN-CVE-2026-27601 · Revision 1Source updated