prompts.chat Identity Confusion via Case-Sensitive Username Handling

{
  "id": "3ebe77dc1c7f221779ffe915d91c119d45a3c65e38c6e6205bc4ce7e8c55c2c6",
  "url": "https://osv.dev/vulnerability/CVE-2026-22665",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "prompts.chat Identity Confusion via Case-Sensitive Username Handling",
    "summary": "prompts.chat prior to commit 1464475, contains an identity confusion vulnerability due to inconsistent case-sensitive and case-insensitive handling of usernames across write and read paths, allowing attackers to create case-variant usernames that bypass uniqueness checks. Attackers can exploit non-deterministic username resolution to impersonate victim accounts, replace profile content on canonical URLs, and inject attacker-controlled metadata and content across the platform.",
    "evidence": "osv:CVE-2026-22665",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-22665",
      "aliases": [
        "CVE-2026-22665"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/f/prompts.chat",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1464475df2698fb7ccd0cdbc382b0750466f891d"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1464475df2698fb7ccd0cdbc382b0750466f891d"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "1464475df2698fb7ccd0cdbc382b0750466f891d"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-22665.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:22.051646865Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22665.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-22665",
        "https://www.vulncheck.com/advisories/prompts-chat-identity-confusion-via-case-sensitive-username-handling",
        "https://github.com/f/prompts.chat/pull/1098",
        "https://github.com/f/prompts.chat/commit/1464475df2698fb7ccd0cdbc382b0750466f891d",
        "https://github.com/f/prompts.chat"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-178"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22665.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-22665",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 488184,
  "published_at": "2026-04-03T20:28:10.061+00:00"
}