morgan vulnerable to Log Injection via unescaped double quote in quoted log fields
### Impact Morgan writes attacker-controlled request data to the access log. Its escaping (added in 1.11.0 and 1.12.0) neutralizes control characters, the Unicode line separators, and backslash, but not the double quote (`0x22`), which is the field delimiter of the Apache combined log format morgan emits. An attacker who controls a quoted field (`:user-agent`, `:referrer`, the request URL, or the Basic auth `:remote-user`) can inject a double quote to close the field early and forge additional fields in the log record. The `combined`, `common`, and `default` formats, and any custom format that quotes a token, are affected. This is an incomplete fix of CVE-2026-5078 and CVE-2026-15603. ### Patches Users should upgrade to version 1.12.1. ### Workarounds Update to version 1.12.1.
GHSA-9f6g-j8ch-79g4
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:GHSA-9f6g-j8ch-79g4
morgan
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 1.12.1
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "1.12.1"
}
]
}
],
"package": {
"name": "morgan",
"purl": "pkg:npm/morgan",
"ecosystem": "npm"
},
"database_specific": {
"source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-9f6g-j8ch-79g4/GHSA-9f6g-j8ch-79g4.json"
}
}
]- Related CVEs
- CVE-2026-87859
Source reference:
/aliases
Publisher severity
No explicit severity was provided.
- Event
- #23689 · Revision 1
- Added to Heist Feed
- Publisher date