Vulnerability-Lookup

GHSA-8F24-V5VV-GM5J

Vulnerability from github – Published: 2026-04-10 21:03 – Updated: 2026-04-24 20:48

Summary

next-intl has an open redirect vulnerability

Details

Impact

Applications using the next-intl middleware with localePrefix: 'as-needed' could construct URLs where path handling and the WHATWG URL parser resolved a relative redirect target to another host (e.g. scheme-relative // or control characters stripped by the URL parser), so the middleware could redirect the browser off-site while the user still started from a trusted app URL.

Patches

The problem has been patched, please update to next-intl@4.9.1.

Credits

Many thanks to Joni Liljeblad from Oura for responsibly disclosing the vulnerability and for suggesting the fix.

Severity

6.9 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "next-intl"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.9.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-40299"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-10T21:03:55Z",
    "nvd_published_at": "2026-04-17T21:16:34Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nApplications using the `next-intl` middleware with `localePrefix: \u0027as-needed\u0027` could construct URLs where path handling and the WHATWG URL parser resolved a relative redirect target to another host (e.g. scheme-relative `//` or control characters stripped by the URL parser), so the middleware could redirect the browser off-site while the user still started from a trusted app URL.\n\n### Patches\n\nThe problem has been patched, please update to [`next-intl@4.9.1`](https://github.com/amannn/next-intl/releases/tag/v4.9.1).\n\n### Credits\n\nMany thanks to [Joni Liljeblad](https://github.com/joniumGit) from [Oura](https://ouraring.com) for responsibly disclosing the vulnerability and for suggesting the fix.",
  "id": "GHSA-8f24-v5vv-gm5j",
  "modified": "2026-04-24T20:48:37Z",
  "published": "2026-04-10T21:03:55Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/amannn/next-intl/security/advisories/GHSA-8f24-v5vv-gm5j"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-40299"
    },
    {
      "type": "WEB",
      "url": "https://github.com/amannn/next-intl/pull/2304"
    },
    {
      "type": "WEB",
      "url": "https://github.com/amannn/next-intl/commit/1c80b668aa6d853f470319eec10a3f61e78a70e6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/amannn/next-intl"
    },
    {
      "type": "WEB",
      "url": "https://github.com/amannn/next-intl/releases/tag/v4.9.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "next-intl has an open redirect vulnerability"
}

CVE-2026-40299 (GCVE-0-2026-40299)

Vulnerability from cvelistv5 – Published: 2026-04-17 20:49 – Updated: 2026-04-20 15:58

Title

next-intl has an open redirect vulnerability

Summary

next-intl provides internationalization for Next.js. Applications using the `next-intl` middleware prior to version 4.9.1with `localePrefix: 'as-needed'` could construct URLs where path handling and the WHATWG URL parser resolved a relative redirect target to another host (e.g. scheme-relative `//` or control characters stripped by the URL parser), so the middleware could redirect the browser off-site while the user still started from a trusted app URL. The problem has been patchedin `next-intl@4.9.1`.

Severity

6.9 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-20 15:56 UTC

CWE

CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')

Assigner

GitHub_M mitre root Scorecard

References

4 references

URL	Tags
https://github.com/amannn/next-intl/security/advi…	x_refsource_CONFIRM
https://github.com/amannn/next-intl/pull/2304	x_refsource_MISC
https://github.com/amannn/next-intl/commit/1c80b6…	x_refsource_MISC
https://github.com/amannn/next-intl/releases/tag/v4.9.1	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
amannn	next-intl	Affected: < 4.9.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-40299",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-20T15:56:01.407919Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-20T15:58:51.149Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "next-intl",
          "vendor": "amannn",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 4.9.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "next-intl provides internationalization for Next.js. Applications using the `next-intl` middleware prior to version 4.9.1with `localePrefix: \u0027as-needed\u0027` could construct URLs where path handling and the WHATWG URL parser resolved a relative redirect target to another host (e.g. scheme-relative `//` or control characters stripped by the URL parser), so the middleware could redirect the browser off-site while the user still started from a trusted app URL. The problem has been patchedin `next-intl@4.9.1`."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 6.9,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-601",
              "description": "CWE-601: URL Redirection to Untrusted Site (\u0027Open Redirect\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-04-17T20:49:05.642Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/amannn/next-intl/security/advisories/GHSA-8f24-v5vv-gm5j",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/amannn/next-intl/security/advisories/GHSA-8f24-v5vv-gm5j"
        },
        {
          "name": "https://github.com/amannn/next-intl/pull/2304",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/amannn/next-intl/pull/2304"
        },
        {
          "name": "https://github.com/amannn/next-intl/commit/1c80b668aa6d853f470319eec10a3f61e78a70e6",
          "tags": [
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          ],
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        },
        {
          "name": "https://github.com/amannn/next-intl/releases/tag/v4.9.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/amannn/next-intl/releases/tag/v4.9.1"
        }
      ],
      "source": {
        "advisory": "GHSA-8f24-v5vv-gm5j",
        "discovery": "UNKNOWN"
      },
      "title": "next-intl has an open redirect vulnerability"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
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    "datePublished": "2026-04-17T20:49:05.642Z",
    "dateReserved": "2026-04-10T20:22:44.035Z",
    "dateUpdated": "2026-04-20T15:58:51.149Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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.

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