Vulnerability-Lookup

FKIE_CVE-2026-90982

Vulnerability from fkie_nvd - Published: 2026-09-17 07:16 - Updated: 2026-09-17 13:16

Severity

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

Summary

@fastify/static is a Fastify plugin that serves static files from a configured root directory. In versions before 10.1.4, on a case-insensitive filesystem such as Windows or the default macOS volume, a route guard or allowedPath restriction can be bypassed by altering the letter case of a path segment. The route matcher is case-sensitive while the filesystem is not, so a request that changes the case of a protected segment does not match the guarded route and falls through to the static handler, yet the filesystem resolves it to the same protected file. As a result, an unauthenticated request can read a file that a route guard or allowedPath was configured to protect. The issue does not affect case-sensitive filesystems and is not a directory traversal, since nothing is served from outside the configured root. The issue is fixed in @fastify/static 10.1.4, which validates the requested path against its actual on-disk spelling and rejects case-aliased paths before authorization. As a workaround, serve static files from a case-sensitive filesystem, or ensure route guards and allowedPath rules account for every letter-case variant of the protected paths.

References

	URL	Tags
	ce714d77-add3-4f53-aff5-83d477b104bb	https://cna.openjsf.org/security-advisories.html
	ce714d77-add3-4f53-aff5-83d477b104bb	https://github.com/fastify/fastify-static/security/advisories/GHSA-r799-r9gc-m956

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/@fastify/static",
          "product": "@fastify/static",
          "vendor": "@fastify/static",
          "versions": [
            {
              "lessThan": "10.1.4",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "10.1.4",
              "versionType": "semver"
            }
          ]
        }
      ],
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "@fastify/static is a Fastify plugin that serves static files from a configured root directory. In versions before 10.1.4, on a case-insensitive filesystem such as Windows or the default macOS volume, a route guard or allowedPath restriction can be bypassed by altering the letter case of a path segment. The route matcher is case-sensitive while the filesystem is not, so a request that changes the case of a protected segment does not match the guarded route and falls through to the static handler, yet the filesystem resolves it to the same protected file. As a result, an unauthenticated request can read a file that a route guard or allowedPath was configured to protect. The issue does not affect case-sensitive filesystems and is not a directory traversal, since nothing is served from outside the configured root. The issue is fixed in @fastify/static 10.1.4, which validates the requested path against its actual on-disk spelling and rejects case-aliased paths before authorization. As a workaround, serve static files from a case-sensitive filesystem, or ensure route guards and allowedPath rules account for every letter-case variant of the protected paths."
    }
  ],
  "id": "CVE-2026-90982",
  "lastModified": "2026-09-17T13:16:58.910",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-90982",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-09-17T12:32:46.853799Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-17T07:16:28.647",
  "references": [
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "url": "https://cna.openjsf.org/security-advisories.html"
    },
    {
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "url": "https://github.com/fastify/fastify-static/security/advisories/GHSA-r799-r9gc-m956"
    }
  ],
  "sourceIdentifier": "ce714d77-add3-4f53-aff5-83d477b104bb",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-178"
        },
        {
          "lang": "en",
          "value": "CWE-284"
        }
      ],
      "source": "ce714d77-add3-4f53-aff5-83d477b104bb",
      "type": "Secondary"
    }
  ]
}

CVE-2026-90982 (GCVE-0-2026-90982)

Vulnerability from cvelistv5 – Published: 2026-09-17 06:55 – Updated: 2026-09-17 12:33

Title

@fastify/static vulnerable to route guard bypass via path case-folding

Summary

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-17 12:32 UTC

CWE

CWE-178 - Improper Handling of Case Sensitivity
CWE-284 - Improper Access Control

Assigner

openjs redhat root

References

2 references

URL	Tags
https://github.com/fastify/fastify-static/securit…
https://cna.openjsf.org/security-advisories.html

Impacted products

1 product

Vendor	Product	Version
@fastify/static	@fastify/static	Affected: 0 , < 10.1.4 (semver) Unaffected: 10.1.4 (semver)

Credits

0xRenSec mcollina UlisesGascon

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-90982",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-17T12:32:46.853799Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-09-17T12:33:23.661Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
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          "defaultStatus": "unaffected",
          "packageURL": "pkg:npm/@fastify/static",
          "product": "@fastify/static",
          "vendor": "@fastify/static",
          "versions": [
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              "version": "0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "10.1.4",
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        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "0xRenSec"
        },
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "mcollina"
        },
        {
          "lang": "en",
          "type": "remediation reviewer",
          "value": "UlisesGascon"
        }
      ],
      "descriptions": [
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              "type": "text/html",
              "value": "@fastify/static is a Fastify plugin that serves static files from a configured root directory. In versions before 10.1.4, on a case-insensitive filesystem such as Windows or the default macOS volume, a route guard or allowedPath restriction can be bypassed by altering the letter case of a path segment. The route matcher is case-sensitive while the filesystem is not, so a request that changes the case of a protected segment does not match the guarded route and falls through to the static handler, yet the filesystem resolves it to the same protected file. As a result, an unauthenticated request can read a file that a route guard or allowedPath was configured to protect. The issue does not affect case-sensitive filesystems and is not a directory traversal, since nothing is served from outside the configured root. The issue is fixed in @fastify/static 10.1.4, which validates the requested path against its actual on-disk spelling and rejects case-aliased paths before authorization. As a workaround, serve static files from a case-sensitive filesystem, or ensure route guards and allowedPath rules account for every letter-case variant of the protected paths."
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      "metrics": [
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          "scenarios": [
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          "descriptions": [
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    "dateReserved": "2026-09-14T13:46:58.766Z",
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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.