Vulnerability-Lookup

FKIE_CVE-2026-4926

Vulnerability from fkie_nvd - Published: 2026-03-26 19:17 - Updated: 2026-04-16 18:04

Severity ?

7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Summary

Impact: A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service. Patches: Fixed in version 8.4.0. Workarounds: Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns.

References

	URL	Tags
	ce714d77-add3-4f53-aff5-83d477b104bb	https://cna.openjsf.org/security-advisories.html	Third Party Advisory

Impacted products

	Vendor	Product	Version
	pillarjs	path-to-regexp	*

JSON

To clipboard

{
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:pillarjs:path-to-regexp:*:*:*:*:*:node.js:*:*",
              "matchCriteriaId": "DB421812-F7E3-4CC5-B02B-53CCBFDFB671",
              "versionEndExcluding": "8.4.0",
              "versionStartIncluding": "8.0.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Impact:\n\nA bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service.\n\nPatches:\n\nFixed in version 8.4.0.\n\nWorkarounds:\n\nLimit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns."
    },
    {
      "lang": "es",
      "value": "Impacto:\n\nSe genera una expresi\u00f3n regular defectuosa siempre que se tienen m\u00faltiples grupos opcionales secuenciales (sintaxis de llaves), como `{a}{b}{c}:z`. La expresi\u00f3n regular generada crece exponencialmente con el n\u00famero de grupos, causando denegaci\u00f3n de servicio.\n\nParches:\n\nCorregido en la versi\u00f3n 8.4.0.\n\nSoluciones alternativas:\n\nLimitar el n\u00famero de grupos opcionales secuenciales en los patrones de ruta. Evitar pasar entradas controladas por el usuario como patrones de ruta."
    }
  ],
  "id": "CVE-2026-4926",
  "lastModified": "2026-04-16T18:04:13.123",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
        "type": "Secondary"
      }
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  },
  "published": "2026-03-26T19:17:08.387",
  "references": [
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://cna.openjsf.org/security-advisories.html"
    }
  ],
  "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-400"
        },
        {
          "lang": "en",
          "value": "CWE-1333"
        }
      ],
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "type": "Secondary"
    }
  ]
}

CVE-2026-4926 (GCVE-0-2026-4926)

Vulnerability from cvelistv5 – Published: 2026-03-26 18:59 – Updated: 2026-03-27 19:44

Title

path-to-regexp vulnerable to Denial of Service via sequential optional groups

Summary

Severity ?

7.5 (High)


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

CWE

CWE-400 - Uncontrolled Resource Consumption
CWE-1333 - Inefficient Regular Expression Complexity

Assigner

openjs

References

URL

Tags

https://cna.openjsf.org/security-advisories.html

Impacted products

	Vendor	Product	Version
	path-to-regexp	path-to-regexp	Affected: 8.0.0 , < 8.4.0 (semver) Unaffected: 8.4.0 (semver)

Credits

uug4na blakeembrey UlisesGascon

Show details on NVD website

JSON

To clipboard

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        "metrics": [
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                "id": "CVE-2026-4926",
                "options": [
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                  },
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                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-27T19:44:44.790485Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
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        "providerMetadata": {
          "dateUpdated": "2026-03-27T19:44:53.294Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
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          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/path-to-regexp",
          "product": "path-to-regexp",
          "vendor": "path-to-regexp",
          "versions": [
            {
              "lessThan": "8.4.0",
              "status": "affected",
              "version": "8.0.0",
              "versionType": "semver"
            },
            {
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              "version": "8.4.0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "uug4na"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "blakeembrey"
        },
        {
          "lang": "en",
          "type": "remediation reviewer",
          "value": "UlisesGascon"
        }
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            }
          ],
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        }
      ],
      "metrics": [
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            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
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          "scenarios": [
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            {
              "cweId": "CWE-1333",
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              "type": "CWE"
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        "orgId": "ce714d77-add3-4f53-aff5-83d477b104bb",
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      "references": [
        {
          "url": "https://cna.openjsf.org/security-advisories.html"
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      "title": "path-to-regexp vulnerable to Denial of Service via sequential optional groups",
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  "cveMetadata": {
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    "assignerShortName": "openjs",
    "cveId": "CVE-2026-4926",
    "datePublished": "2026-03-26T18:59:38.000Z",
    "dateReserved": "2026-03-26T18:36:49.229Z",
    "dateUpdated": "2026-03-27T19:44:53.294Z",
    "state": "PUBLISHED"
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  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

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.

Action not permitted

FKIE_CVE-2026-4926

CVE-2026-4926 (GCVE-0-2026-4926)

Tags

Sightings

Nomenclature