{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-66546 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2025-66546 yet. Limit exposure of the affected software until one is available.","what":"CVE-2025-66546 is a low-severity missing authorization vulnerability in nextcloud security-advisories, published on 5 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-66546 and fix it if it is affected.\n\nWhat it is: CVE-2025-66546 is a low-severity missing authorization vulnerability in nextcloud security-advisories, published on 5 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2025-66546 in the wild and no public exploit code.\n\nAffected product: nextcloud security-advisories. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2025-66546/ (Markdown: https://insights.sbomify.com/CVE-2025-66546/index.md)","id":"CVE-2025-66546","markdown":"https://insights.sbomify.com/CVE-2025-66546/index.md","name":"CVE-2025-66546","record":{"aliases":["GHSA-7x2j-2674-fj95"],"analysis":{"component_type":"web_application","fix_type":"patch","impacts":["data_modify"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Nextcloud Calendar app","requires_auth":"low_privilege","summary":"Attackers can book appointments without valid tokens by guessing sequential IDs, allowing unauthorized data modification in Nextcloud Calendar.","user_interaction":"not_required","vuln_class":"missing_authorization"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"calendar","vendor":"nextcloud"}],"cvss":{"score":3.3,"severity":"low","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N","version":"3.1"},"cwes":[{"id":"CWE-639","name":"Authorization Bypass Through User-Controlled Key"}],"description":"Nextcloud Calendar is a calendar app for Nextcloud. Prior to 4.7.19, 5.5.6, and 6.0.1, the calendar app allowed blindly booking appointments with a squential ID without known the appointment token. This vulnerability is fixed in 4.7.19, 5.5.6, and 6.0.1.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"Nextcloud Calendar app allowed booking appointments without the generated token","id":"CVE-2025-66546","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"missing_authorization","year":"2025"},"n_packages":0,"n_references":4,"next":{"headline":"Nextcloud Server users can modify tags on files that do not belong to them","id":"CVE-2025-66547"},"packages":[],"prev":{"headline":"Nextcloud Groupfolders users with read-only permissions for team folder can restore deleted files from trash bin","id":"CVE-2025-66545"},"products":["security-advisories"],"published":"2025-12-05","related":[{"cvss_score":5.7,"headline":"Nextcloud Calendar attachments of local files are offered to downloaded","id":"CVE-2025-66550","kev_date_added":null,"published":"2025-12-05"},{"cvss_score":5.3,"headline":"Command Injection in Appointment Emails for Nextcloud Calendar","id":"CVE-2022-24838","kev_date_added":null,"published":"2022-04-11"},{"cvss_score":4.8,"headline":"Nextcloud Calendar app used predictable proposal participant tokens","id":"CVE-2025-66511","kev_date_added":null,"published":"2025-12-05"},{"cvss_score":4.8,"headline":"Cross-site scripting in Nextcloud Calendar application","id":"CVE-2018-3763","kev_date_added":null,"published":"2018-07-05"},{"cvss_score":4.6,"headline":"Nextcloud Calendar's event create can create attachments that link to other websites","id":"CVE-2024-37316","kev_date_added":null,"published":"2024-06-14"},{"cvss_score":4.3,"headline":"Nextcloud: Calendar app leaked user identifiers via attendee suggestion endpoint","id":"CVE-2026-45286","kev_date_added":null,"published":"2026-06-01"},{"cvss_score":4.3,"headline":"Inviting excessive long email addresses to a calendar event makes the Nextcloud server unresponsive","id":"CVE-2023-45150","kev_date_added":null,"published":"2023-10-16"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2025-12-05","vendors":["nextcloud"]},"summary":"Attackers can book appointments without valid tokens by guessing sequential IDs, allowing unauthorized data modification in Nextcloud Calendar.","url":"https://insights.sbomify.com/CVE-2025-66546/"}