{"answers":{"affected":"1 open source package ship an affected version, including mastodon. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-23961 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-2026-23961 is a medium-severity authentication bypass vulnerability in mastodon, published on 22 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-23961 and fix it if it is affected.\n\nWhat it is: CVE-2026-23961 is a medium-severity authentication bypass vulnerability in mastodon, published on 22 Jan 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-23961 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-2026-23961/ (Markdown: https://insights.sbomify.com/CVE-2026-23961/index.md)","id":"CVE-2026-23961","markdown":"https://insights.sbomify.com/CVE-2026-23961/index.md","name":"CVE-2026-23961","record":{"aliases":["BIT-mastodon-2026-23961","GHSA-5h2f-wg8j-xqwp"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Mastodon social network","requires_auth":"none","summary":"Remote suspended users can bypass suspension restrictions to display posts in timelines, requiring administrators to upgrade Mastodon.","user_interaction":"not_required","vuln_class":"auth_bypass"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mastodon","vendor":"joinmastodon"}],"cvss":{"score":5.3,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"},"cwes":[{"id":"CWE-863","name":"Incorrect Authorization"}],"description":"Mastodon is a free, open-source social network server based on ActivityPub. Mastodon allows server administrators to suspend remote users to prevent interactions. However, some logic errors allow already-known posts from such suspended users to appear in timelines if boosted. Furthermore, under certain circumstances, previously-unknown posts from suspended users can be processed. This issue allows old posts from suspended users to occasionally end up on timelines on all Mastodon versions. Additionally, on Mastodon versions from v4.5.0 to v4.5.4, v4.4.5 to v4.4.11, v4.3.13 to v4.3.17, and v4.2.26 to v4.2.29, remote suspended users can partially bypass the suspension to get new posts in. 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 may allow a remote suspension bypass","id":"CVE-2026-23961","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":null,"products":[],"type":"auth_bypass","year":"2026"},"n_packages":1,"n_references":4,"next":{"headline":"Mastodon vulnerable to Denial of Service from a single post (client/server)","id":"CVE-2026-23962"},"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-2026-23961"}],"prev":{"headline":"Argo Workflows affected by stored XSS in the artifact directory listing","id":"CVE-2026-23960"},"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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-01-22","vendors":["mastodon"]},"summary":"Remote suspended users can bypass suspension restrictions to display posts in timelines, requiring administrators to upgrade Mastodon.","url":"https://insights.sbomify.com/CVE-2026-23961/"}