GHSA-jxfw-x594-9x9m

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Source
https://github.com/advisories/GHSA-jxfw-x594-9x9m
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-jxfw-x594-9x9m/GHSA-jxfw-x594-9x9m.json
JSON Data
https://api.test.osv.dev/v1/vulns/GHSA-jxfw-x594-9x9m
Aliases
Downstream
CGA (6)
MINI (1)
Published
2026-09-08T21:28:26Z
Modified
2026-09-08T21:45:04Z
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 Forging via unescaped Unicode line separators
Details

Impact

Morgan writes attacker-controlled request data to the access log through its tokens. The 1.11.0 fix neutralizes C0 control characters, DEL, and backslash, but it does not escape the Unicode line separators U+0085 (NEL), U+2028 (LINE SEPARATOR), or U+2029 (PARAGRAPH SEPARATOR). These code points are reachable through several tokens, including the request URL (:url), request headers such as :user-agent and :referrer, arbitrary :req[header] values, and the Basic auth username (:remote-user). NEL is valid obs-text in HTTP header values, so an attacker can place it in an ordinary request header.

When such a value is logged, the raw code points survive into the emitted access-log record, and downstream ECMAScript-aware or Unicode-aware log processing splits the single physical record into multiple logical records. This allows an attacker to forge log entries. The built-in combined, common, default, and short formats are affected, as well as any custom format. This is an incomplete fix of CVE-2026-5078.

Patches

Users should upgrade to version 1.12.0.

Workarounds

None. The affected values include the request URL and request headers, which are core to access logging, so there is no practical format-based mitigation. Upgrade to 1.12.0.

Database specific 
{
    "cwe_ids": [
        "CWE-117"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-08T21:28:26Z",
    "nvd_published_at": "2026-08-28T16:17:07Z",
    "severity": "MODERATE"
}
References

Affected packages

npm / morgan

Package

Name
morgan
View open source insights on deps.dev
Purl
pkg:npm/morgan

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.12.0

Database specific

source 
"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-jxfw-x594-9x9m/GHSA-jxfw-x594-9x9m.json"