Vulnerability-Lookup

FKIE_CVE-2026-5078

Vulnerability from fkie_nvd - Published: 2026-06-03 08:16 - Updated: 2026-07-22 19:10

Severity

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

Summary

Impact: The morgan logging middleware's :remote-user token extracts the Basic auth username from the Authorization request header and writes it to the log stream without neutralizing control characters. An unauthenticated attacker can send a crafted Authorization Basic header containing CR or LF bytes to inject forged log lines, breaking the one-request-per-line structure of access logs and enabling log forgery against downstream log consumers. The built-in combined, common, default, and short formats are affected, as well as any custom format that references :remote-user. Affected versions: morgan 1.2.0 through 1.10.1. Patches: upgrade to morgan 1.11.0, which neutralizes control characters in the :remote-user token output. Workarounds: use a custom format string that does not include :remote-user.

References

	URL	Tags
	ce714d77-add3-4f53-aff5-83d477b104bb	https://cna.openjsf.org/security-advisories.html	Third Party Advisory
	ce714d77-add3-4f53-aff5-83d477b104bb	https://github.com/expressjs/morgan/security/advisories/GHSA-4vj7-5mj6-jm8m	Mitigation, Vendor Advisory

Impacted products

	Vendor	Product	Version
	morgan_project	morgan	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/morgan",
          "product": "morgan",
          "vendor": "morgan",
          "versions": [
            {
              "lessThanOrEqual": "1.10.1",
              "status": "affected",
              "version": "1.2.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "1.11.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:morgan_project:morgan:*:*:*:*:*:node.js:*:*",
              "matchCriteriaId": "BB39C2E2-D0C6-4871-944A-08DBC91BC438",
              "versionEndExcluding": "1.11.0",
              "versionStartIncluding": "1.2.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Impact: The morgan logging middleware\u0027s :remote-user token extracts the Basic auth username from the Authorization request header and writes it to the log stream without neutralizing control characters. An unauthenticated attacker can send a crafted Authorization Basic header containing CR or LF bytes to inject forged log lines, breaking the one-request-per-line structure of access logs and enabling log forgery against downstream log consumers. The built-in combined, common, default, and short formats are affected, as well as any custom format that references :remote-user. Affected versions: morgan 1.2.0 through 1.10.1. Patches: upgrade to morgan 1.11.0, which neutralizes control characters in the :remote-user token output. Workarounds: use a custom format string that does not include :remote-user."
    },
    {
      "lang": "es",
      "value": "Impacto: El token :remote-user del middleware de registro morgan extrae el nombre de usuario de autenticaci\u00f3n Basic del encabezado de solicitud de autorizaci\u00f3n y lo escribe en el flujo de registro sin neutralizar los caracteres de control. Un atacante no autenticado puede enviar un encabezado Authorization Basic manipulado que contiene bytes CR o LF para inyectar l\u00edneas de registro falsificadas, rompiendo la estructura de una solicitud por l\u00ednea de los registros de acceso y permitiendo la falsificaci\u00f3n de registros contra los consumidores de registros posteriores. Los formatos integrados combined, common, default y short se ven afectados, as\u00ed como cualquier formato personalizado que haga referencia a :remote-user. Versiones afectadas: morgan 1.2.0 hasta 1.10.1. Parches: actualizar a morgan 1.11.0, que neutraliza los caracteres de control en la salida del token :remote-user. Soluciones alternativas: usar una cadena de formato personalizada que no incluya :remote-user."
    }
  ],
  "id": "CVE-2026-5078",
  "lastModified": "2026-07-22T19:10:00.120",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
          "version": "3.1"
        },
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        "impactScore": 1.4,
        "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
        "type": "Secondary"
      }
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    "ssvcV203": [
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        "ssvcData": {
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          "options": [
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              "exploitation": "none"
            },
            {
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          "role": "CISA Coordinator",
          "timestamp": "2026-06-03T13:16:59.663217Z",
          "version": "2.0.3"
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  "published": "2026-06-03T08:16:19.743",
  "references": [
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "tags": [
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      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "tags": [
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    }
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  "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb",
  "vulnStatus": "Analyzed",
  "weaknesses": [
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        {
          "lang": "en",
          "value": "CWE-117"
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      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "type": "Secondary"
    }
  ]
}

CVE-2026-5078 (GCVE-0-2026-5078)

Vulnerability from cvelistv5 – Published: 2026-06-03 05:56 – Updated: 2026-06-03 13:19

Title

morgan vulnerable to Log Forging via unneutralized control characters in :remote-user

Summary

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-03 13:16 UTC

CWE

CWE-117 - Improper Output Neutralization for Logs

Assigner

openjs redhat root

References

2 references

URL	Tags
https://github.com/expressjs/morgan/security/advi…
https://cna.openjsf.org/security-advisories.html

Impacted products

1 product

Vendor	Product	Version
morgan	morgan	Affected: 1.2.0 , ≤ 1.10.1 (semver) Unaffected: 1.11.0 (semver)

Credits

Yuki Matsuhashi Ulises Gascón Jon Church

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-5078",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-03T13:16:59.663217Z",
                "version": "2.0.3"
              },
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          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/morgan",
          "product": "morgan",
          "vendor": "morgan",
          "versions": [
            {
              "lessThanOrEqual": "1.10.1",
              "status": "affected",
              "version": "1.2.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "1.11.0",
              "versionType": "semver"
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      "credits": [
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          "lang": "en",
          "type": "reporter",
          "value": "Yuki Matsuhashi"
        },
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          "type": "remediation developer",
          "value": "Ulises Gasc\u00f3n"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Jon Church"
        }
      ],
      "descriptions": [
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            {
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              "type": "text/html",
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            }
          ],
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      "metrics": [
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            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
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            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
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          "scenarios": [
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              "lang": "en",
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        "orgId": "ce714d77-add3-4f53-aff5-83d477b104bb",
        "shortName": "openjs"
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      "references": [
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          "url": "https://github.com/expressjs/morgan/security/advisories/GHSA-4vj7-5mj6-jm8m"
        },
        {
          "url": "https://cna.openjsf.org/security-advisories.html"
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    "cveId": "CVE-2026-5078",
    "datePublished": "2026-06-03T05:56:49.512Z",
    "dateReserved": "2026-03-28T17:42:51.328Z",
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    "state": "PUBLISHED"
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.