CVE-2026-87859

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Source

https://cve.org/CVERecord?id=CVE-2026-87859

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-87859.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-87859

Aliases

GHSA-9f6g-j8ch-79g4

Downstream

DEBIAN-CVE-2026-87859

UBUNTU-CVE-2026-87859

Published

2026-09-11T09:15:19Z

Modified

2026-09-18T03:30:22Z

Severity

5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N CVSS Calculator

Summary

morgan vulnerable to Log Injection via unescaped double quote in quoted log fields

Details

morgan is an HTTP request logger middleware for Node.js. In versions before 1.12.1, its escapeLogField() function does not escape the double quote character, which delimits the quoted fields of the Apache combined log format that morgan emits. An unauthenticated remote attacker who controls a value written to a quoted field, such as the User-Agent or Referer header, can include a double quote to close that field early, so a log consumer that parses the log by field position reads attacker-supplied text as the following field. In the built-in formats this makes the recorded value differ from the value that was sent, and in custom formats that quote an attacker-controlled token before a server-controlled one it can forge values such as the response status. No newline is injected, so record separation stays intact. The issue is fixed in morgan 1.12.1, which escapes the double quote. Users should upgrade to morgan 1.12.1 or later.

Database specific

{
    "cna_assigner": "openjs",
    "cwe_ids": [
        "CWE-117"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/87xxx/CVE-2026-87859.json"
}

References

Affected packages

Git / github.com/expressjs/morgan

Affected ranges

Type

GIT

Repo

https://github.com/expressjs/morgan

Events

Introduced

Fixed

b1272e70812dbc504321eeb5a43d14b0822c150d

Database specific

Show details

{
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "1.12.1"
        }
    ],
    "source": [
        "AFFECTED_FIELD",
        "DESCRIPTION"
    ]
}

Affected versions

1.*

1.0.0

1.0.1

1.1.0

1.1.1

1.10.0

1.11.0

1.12.0

1.2.0

1.2.1

1.2.2

1.2.3

1.3.0

1.3.1

1.3.2

1.4.0

1.4.1

1.5.0

1.5.1

1.5.2

1.5.3

1.6.0

1.6.1

1.7.0

1.8.0

1.8.1

1.8.2

1.9.0

1.9.1

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-87859.json"