{"answers":{"affected":"1 open source package ship an affected version, including mastodon. It affects 1 product.","exploited":"There is no known exploitation of CVE-2026-27477 in the wild and no public exploit code.","fix":"Upgrade mastodon to a fixed version for your release line: 4.4.14 or 4.5.7.","what":"CVE-2026-27477 is a medium-severity server-side request forgery vulnerability in mastodon, published on 24 Feb 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-2026-27477 and fix it if it is affected.\n\nWhat it is: CVE-2026-27477 is a medium-severity server-side request forgery vulnerability in mastodon, published on 24 Feb 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-2026-27477 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- mastodon (Bitnami): affected from 4.4.0; fixed in 4.4.14, 4.5.7\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-2026-27477/ (Markdown: https://insights.sbomify.com/CVE-2026-27477/index.md)","id":"CVE-2026-27477","markdown":"https://insights.sbomify.com/CVE-2026-27477/index.md","name":"CVE-2026-27477","record":{"aliases":["BIT-mastodon-2026-27477","GHSA-46w6-g98f-wxqm"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":true,"product_category":"Mastodon social network","requires_auth":"none","summary":"An attacker can force the Mastodon server to make requests to internal systems via unvalidated FASP base_url, requiring the experimental feature to be enabled.","user_interaction":"not_required","vuln_class":"ssrf"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mastodon","vendor":"joinmastodon"}],"cvss":{"score":4.6,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U","version":"4.0"},"cwes":[{"id":"CWE-918","name":"Server-Side Request Forgery"}],"description":"Mastodon is a free, open-source social network server based on ActivityPub. FASP registration requires manual approval by an administrator. In versions 4.4.0 through 4.4.13 and 4.5.0 through 4.5.6, an unauthenticated attacker can register a FASP with an attacker-chosen `base_url` that includes or resolves to a local / internal address, leading to the Mastodon server making requests to that address. This only affects Mastodon servers that have opted in to testing the experimental FASP feature by setting the environment variable `EXPERIMENTAL_FEATURES` to a value including `fasp`. An attacker can force the Mastodon server to make http(s) requests to internal systems. While they cannot control the full URL that is being requested (only the prefix) and cannot see the result of those requests, vulnerabilities or other undesired behavior could be triggered in those systems. The fix is included in the 4.4.14 and 4.5.7 releases. Admins that are actively testing the experimental \"fasp\" feature should update their systems. Servers not using the experimental feature flag `fasp` are not affected.","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 has SSRF via unvalidated FASP Provider base_url","id":"CVE-2026-27477","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Bitnami","product":null,"products":[],"type":"ssrf","year":"2026"},"n_packages":1,"n_references":2,"next":{"headline":"Unity Catalog has a JWT Issuer Validation Bypass Allows Complete User Impersonation","id":"CVE-2026-27478"},"packages":[{"ecosystem":"Bitnami","fixed":["4.4.14","4.5.7"],"introduced":["4.4.0","4.5.0"],"last_affected":[],"package":"mastodon","purl":"pkg:bitnami/mastodon","source":"BIT-mastodon-2026-27477"}],"prev":{"headline":"RustFly 2.0.0 Command Injection via UDP Remote Control","id":"CVE-2026-27476"},"products":["mastodon"],"published":"2026-02-24","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":"2026-02-26","vendors":["mastodon"]},"summary":"An attacker can force the Mastodon server to make requests to internal systems via unvalidated FASP base_url, requiring the experimental feature to be enabled.","url":"https://insights.sbomify.com/CVE-2026-27477/"}