Vulnerability-Lookup

PYSEC-2026-2197

Vulnerability from pysec - Published: 2026-02-09 20:15 - Updated: 2026-07-13 05:49

Details

Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. Prior to 2.20.0, FileStore maps cache keys to filenames using Unicode NFKD normalization and ord() substitution without separators, creating key collisions. When FileStore is used as response-cache backend, an unauthenticated remote attacker can trigger cache key collisions via crafted paths, causing one URL to serve cached responses of another (cache poisoning/mixup). This vulnerability is fixed in 2.20.0.

Severity

6.5 (Medium)


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

Impacted products

Name	purl
litestar	pkg:pypi/litestar

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {},
      "package": {
        "ecosystem": "PyPI",
        "name": "litestar",
        "purl": "pkg:pypi/litestar"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.20.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.0.0a0",
        "2.0.0",
        "2.0.0a3",
        "2.0.0a4",
        "2.0.0a5",
        "2.0.0a6",
        "2.0.0a7",
        "2.0.0b1",
        "2.0.0b2",
        "2.0.0b3",
        "2.0.0b4",
        "2.0.0rc1",
        "2.0.1",
        "2.1.0",
        "2.1.1",
        "2.10.0",
        "2.11.0",
        "2.12.0",
        "2.12.1",
        "2.13.0",
        "2.14.0",
        "2.15.0",
        "2.15.1",
        "2.15.2",
        "2.16.0",
        "2.17.0",
        "2.18.0",
        "2.19.0",
        "2.2.0",
        "2.2.1",
        "2.3.0",
        "2.3.1",
        "2.3.2",
        "2.4.0",
        "2.4.1",
        "2.4.2",
        "2.4.3",
        "2.4.4",
        "2.4.5",
        "2.5.0",
        "2.5.1",
        "2.5.2",
        "2.5.3",
        "2.5.4",
        "2.5.5",
        "2.6.0",
        "2.6.1",
        "2.6.2",
        "2.6.3",
        "2.6.4",
        "2.7.0",
        "2.7.1",
        "2.7.2",
        "2.8.0",
        "2.8.1",
        "2.8.2",
        "2.8.3",
        "2.9.0",
        "2.9.1"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-25480",
    "GHSA-vxqx-rh46-q2pg"
  ],
  "details": "Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. Prior to 2.20.0, FileStore maps cache keys to filenames using Unicode NFKD normalization and ord() substitution without separators, creating key collisions. When FileStore is used as response-cache backend, an unauthenticated remote attacker can trigger cache key collisions via crafted paths, causing one URL to serve cached responses of another (cache poisoning/mixup). This vulnerability is fixed in 2.20.0.",
  "id": "PYSEC-2026-2197",
  "modified": "2026-07-13T05:49:37.107489Z",
  "published": "2026-02-09T20:15:57.330Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/litestar-org/litestar/releases/tag/v2.20.0"
    },
    {
      "type": "FIX",
      "url": "https://github.com/litestar-org/litestar/commit/85db6183a76f8a6b3fd6ee3c88d860b9f37a2cca"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/litestar-org/litestar/security/advisories/GHSA-vxqx-rh46-q2pg"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-25480 (GCVE-0-2026-25480)

Vulnerability from cvelistv5 – Published: 2026-02-09 18:49 – Updated: 2026-02-10 16:01

Title

FileStore key canonicalization collisions allow response cache mixup/poisoning (ASCII ord + Unicode NFKD)

Summary

Severity

6.5 (Medium)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-176 - Improper Handling of Unicode Encoding

Assigner

GitHub_M

References

4 references

URL	Tags
https://github.com/litestar-org/litestar/security…	x_refsource_CONFIRM
https://github.com/litestar-org/litestar/commit/8…	x_refsource_MISC
https://docs.litestar.dev/2/release-notes/changel…	x_refsource_MISC
https://github.com/litestar-org/litestar/releases…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
litestar-org	litestar	Affected: < 2.20.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-25480",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-10T15:39:52.216141Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-02-10T16:01:06.327Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "litestar",
          "vendor": "litestar-org",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.20.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. Prior to 2.20.0, FileStore maps cache keys to filenames using Unicode NFKD normalization and ord() substitution without separators, creating key collisions. When FileStore is used as response-cache backend, an unauthenticated remote attacker can trigger cache key collisions via crafted paths, causing one URL to serve cached responses of another (cache poisoning/mixup). This vulnerability is fixed in 2.20.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.5,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-176",
              "description": "CWE-176: Improper Handling of Unicode Encoding",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-09T18:49:34.305Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/litestar-org/litestar/security/advisories/GHSA-vxqx-rh46-q2pg",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/litestar-org/litestar/security/advisories/GHSA-vxqx-rh46-q2pg"
        },
        {
          "name": "https://github.com/litestar-org/litestar/commit/85db6183a76f8a6b3fd6ee3c88d860b9f37a2cca",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/litestar-org/litestar/commit/85db6183a76f8a6b3fd6ee3c88d860b9f37a2cca"
        },
        {
          "name": "https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0"
        },
        {
          "name": "https://github.com/litestar-org/litestar/releases/tag/v2.20.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/litestar-org/litestar/releases/tag/v2.20.0"
        }
      ],
      "source": {
        "advisory": "GHSA-vxqx-rh46-q2pg",
        "discovery": "UNKNOWN"
      },
      "title": "FileStore key canonicalization collisions allow response cache mixup/poisoning (ASCII ord + Unicode NFKD)"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-25480",
    "datePublished": "2026-02-09T18:49:34.305Z",
    "dateReserved": "2026-02-02T16:31:35.821Z",
    "dateUpdated": "2026-02-10T16:01:06.327Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

GHSA-VXQX-RH46-Q2PG

Vulnerability from github – Published: 2026-02-09 17:19 – Updated: 2026-02-09 22:38

Summary

Litestar's FileStore key canonicalization collisions allow response cache mixup/poisoning (ASCII ord + Unicode NFKD)

Details

Summary

FileStore maps cache keys to filenames using Unicode NFKD normalization and ord() substitution without separators, creating key collisions. When FileStore is used as response-cache backend, an unauthenticated remote attacker can trigger cache key collisions via crafted paths, causing one URL to serve cached responses of another (cache poisoning/mixup)

Details

litestar.stores.file._safe_file_name() normalizes input with unicodedata.normalize("NFKD", name) and builds the filename by concatenating c if alphanumeric else str(ord(c)) (no delimiter). This transformation is not injective, e.g.:

"k-" and "k45" both become "k45" (because - ord('-') == 45)
"k/\n" becomes "k4710", colliding with "k4710"
"K" (Kelvin sign) normalizes to "K", colliding with "K"

When used in response caching, the default cache key includes request path and sorted query params, which are attacker-controlled.

PoC

import asyncio, tempfile
from litestar.stores.file import FileStore

async def main():
    d = tempfile.mkdtemp(prefix="ls_filestore_poc_")
    store = FileStore(d, create_directories=True)
    await store.__aenter__()

    # 1) ASCII ord-collision: "-" -> 45
    await store.set("k-", b"A")
    v = await store.get("k45")
    print("k-  ->", v)
    print("k45 ->", await store.get("k45"))
    if v == b"A":
        print("VULNERABLE: 'k-' collides with 'k45'")

    # 2) NFKD collision: Kelvin sign -> K
    await store.set("K", b"B")   # U+212A
    v2 = await store.get("K")
    print("K ->", await store.get("K"))
    print("K ->", v2)
    if v2 == b"B":
        print("VULNERABLE: 'K' collides with 'K' (NFKD)")

if __name__ == "__main__":
    asyncio.run(main())

Impact

Vulnerability type: cache poisoning / cache key collision. Impacted deployments: applications using Litestar response caching with FileStore backend (or any attacker-influenced keying into FileStore). Possible impact: serving incorrect cached content across distinct URLs, potential confidentiality/integrity issues depending on what endpoints are cached.

Severity

6.5 (Medium)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "litestar"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.19.0"
            },
            {
              "fixed": "2.20.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "2.19.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-25480"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-176",
      "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-09T17:19:06Z",
    "nvd_published_at": "2026-02-09T20:15:57Z",
    "severity": "MODERATE"
  },
  "details": "### Summary\nFileStore maps cache keys to filenames using Unicode NFKD normalization and ord() substitution without separators, creating key collisions. When FileStore is used as response-cache backend, an unauthenticated remote attacker can trigger cache key collisions via crafted paths, causing one URL to serve cached responses of another (cache poisoning/mixup)\n\n### Details\nlitestar.stores.file._safe_file_name() normalizes input with unicodedata.normalize(\"NFKD\", name) and builds the filename by concatenating c if alphanumeric else str(ord(c)) (no delimiter).\nThis transformation is not injective, e.g.:\n\n- \"k-\" and \"k45\" both become \"k45\" (because - ord(\u0027-\u0027) == 45)\n- \"k/\\n\" becomes \"k4710\", colliding with \"k4710\"\n- \"\u212a\" (Kelvin sign) normalizes to \"K\", colliding with \"K\"\n\nWhen used in response caching, the default cache key includes request path and sorted query params, which are attacker-controlled.\n\n### PoC\n\n```\nimport asyncio, tempfile\nfrom litestar.stores.file import FileStore\n\nasync def main():\n    d = tempfile.mkdtemp(prefix=\"ls_filestore_poc_\")\n    store = FileStore(d, create_directories=True)\n    await store.__aenter__()\n\n    # 1) ASCII ord-collision: \"-\" -\u003e 45\n    await store.set(\"k-\", b\"A\")\n    v = await store.get(\"k45\")\n    print(\"k-  -\u003e\", v)\n    print(\"k45 -\u003e\", await store.get(\"k45\"))\n    if v == b\"A\":\n        print(\"VULNERABLE: \u0027k-\u0027 collides with \u0027k45\u0027\")\n\n    # 2) NFKD collision: Kelvin sign -\u003e K\n    await store.set(\"\u212a\", b\"B\")   # U+212A\n    v2 = await store.get(\"K\")\n    print(\"\u212a -\u003e\", await store.get(\"\u212a\"))\n    print(\"K -\u003e\", v2)\n    if v2 == b\"B\":\n        print(\"VULNERABLE: \u0027\u212a\u0027 collides with \u0027K\u0027 (NFKD)\")\n\nif __name__ == \"__main__\":\n    asyncio.run(main())\n```\n\n### Impact\nVulnerability type: cache poisoning / cache key collision.\nImpacted deployments: applications using Litestar response caching with FileStore backend (or any attacker-influenced keying into FileStore).\nPossible impact: serving incorrect cached content across distinct URLs, potential confidentiality/integrity issues depending on what endpoints are cached.",
  "id": "GHSA-vxqx-rh46-q2pg",
  "modified": "2026-02-09T22:38:14Z",
  "published": "2026-02-09T17:19:06Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/litestar-org/litestar/security/advisories/GHSA-vxqx-rh46-q2pg"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-25480"
    },
    {
      "type": "WEB",
      "url": "https://github.com/litestar-org/litestar/commit/85db6183a76f8a6b3fd6ee3c88d860b9f37a2cca"
    },
    {
      "type": "WEB",
      "url": "https://docs.litestar.dev/2/release-notes/changelog.html#2.20.0"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/litestar-org/litestar"
    },
    {
      "type": "WEB",
      "url": "https://github.com/litestar-org/litestar/releases/tag/v2.20.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Litestar\u0027s FileStore key canonicalization collisions allow response cache mixup/poisoning (ASCII ord + Unicode NFKD)"
}

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.

Action not permitted

PYSEC-2026-2197

CVE-2026-25480 (GCVE-0-2026-25480)

GHSA-VXQX-RH46-Q2PG

Summary

Details

PoC

Impact

Tags

Sightings

Nomenclature