{"answers":{"affected":"1 open source package ship an affected version, including mastodon. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23963 in the wild and no public exploit code.","fix":"Upgrade mastodon to a fixed version for your release line: 4.3.18, 4.4.12 or 4.5.5.","what":"CVE-2026-23963 is a medium-severity denial of service vulnerability in mastodon, published on 22 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-23963 and fix it if it is affected.\n\nWhat it is: CVE-2026-23963 is a medium-severity denial of service vulnerability in mastodon, published on 22 Jan 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-23963 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- mastodon (Bitnami): affected all versions; fixed in 4.3.18, 4.4.12, 4.5.5\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-2026-23963/ (Markdown: https://insights.sbomify.com/CVE-2026-23963/index.md)","id":"CVE-2026-23963","markdown":"https://insights.sbomify.com/CVE-2026-23963/index.md","name":"CVE-2026-23963","record":{"aliases":["BIT-mastodon-2026-23963","GHSA-6x3w-9g92-gvf3"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Mastodon social network","requires_auth":"low_privilege","summary":"Attackers can cause resource exhaustion and service disruption by submitting arbitrarily long strings in list and filter fields.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mastodon","vendor":"joinmastodon"}],"cvss":{"score":4.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L","version":"3.1"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"}],"description":"Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.5.5, 4.4.12, and 4.3.18, the server does not enforce a maximum length for the names of lists or filters, or for filter keywords, allowing any user to set an arbitrarily long string as the name or keyword. Any local user can abuse the list or filter fields to cause disproportionate storage and computing resource usage. They can additionally cause their own web interface to be unusable, although they must intentionally do this to themselves or unknowingly approve a malicious API client. Mastodon versions v4.5.5, v4.4.12, v4.3.18 are patched.","ecosystems":["Bitnami"],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Mastodon missing length limits on list names, filter names, and filter keywords","id":"CVE-2026-23963","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":null,"products":[],"type":"denial_of_service","year":"2026"},"n_packages":1,"n_references":4,"next":{"headline":"Mastodon has insufficient access control to push notification settings","id":"CVE-2026-23964"},"packages":[{"ecosystem":"Bitnami","fixed":["4.3.18","4.4.12","4.5.5"],"introduced":["0","4.4.0","4.5.0"],"last_affected":[],"package":"mastodon","purl":"pkg:bitnami/mastodon","source":"BIT-mastodon-2026-23963"}],"prev":{"headline":"Mastodon vulnerable to Denial of Service from a single post (client/server)","id":"CVE-2026-23962"},"products":["mastodon"],"published":"2026-01-22","related":[{"cvss_score":10,"headline":"Mastodon vulnerable to arbitrary file creation through media attachments","id":"CVE-2023-36460","kev_date_added":null,"published":"2023-07-06"},{"cvss_score":9.8,"headline":"Improper Restriction of Excessive Authentication Attempts in mastodon/mastodon","id":"CVE-2022-2166","kev_date_added":null,"published":"2022-11-16"},{"cvss_score":9.8,"headline":"Missing authorization in n/a","id":"CVE-2022-24307","kev_date_added":null,"published":"2022-02-03"},{"cvss_score":9.8,"headline":"Auth bypass in n/a","id":"CVE-2018-21018","kev_date_added":null,"published":"2019-09-22"},{"cvss_score":9.4,"headline":"Mastodon Remote user impersonation and takeover","id":"CVE-2024-23832","kev_date_added":null,"published":"2024-02-01"},{"cvss_score":9.3,"headline":"Mastodon vulnerable to Cross-site Scripting through oEmbed preview cards","id":"CVE-2023-36459","kev_date_added":null,"published":"2023-07-06"},{"cvss_score":8.5,"headline":"Lack of media type verification of Activity Streams objects allows impersonation of remote accounts","id":"CVE-2024-25623","kev_date_added":null,"published":"2024-02-19"}],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"Bitnami","prefix":"BIT"},{"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":"2026-01-22","vendors":["mastodon"]},"summary":"Attackers can cause resource exhaustion and service disruption by submitting arbitrarily long strings in list and filter fields.","url":"https://insights.sbomify.com/CVE-2026-23963/"}