{"id":"CVE-2026-123201","kind":"vulnerability","aliases":["CVE-2026-123201"],"related":[],"title":"Buku bukuserver: unauthenticated request forgery lets remote users read internal services","description":"Buku (bukuserver) through 5.1.1 contains an unauthenticated server-side request forgery vulnerability that allows remote attackers to make the server request internal hosts by supplying a url parameter to /api/fetch_data or /api/network_handle. Attackers can target loopback, private, or cloud metadata IP addresses, which pass the weak is_bad_url() check and follow redirects, to discover internal services and read their page titles, descriptions, and keywords.","summary":"Buku's bukuserver web interface lets an unauthenticated remote attacker make the server request internal hosts through the url parameter of /api/fetch_data or /api/network_handle. The attacker can read the page titles, descriptions and keywords of loopback, private and cloud metadata addresses.","severity":"medium","cvss":6.3,"epss":null,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["buku","bukuserver","package","python","self-hosted"],"not_affected_if":["bukuserver-not-running","cli-only-use"],"how_to_check":"- Check whether bukuserver is running and reachable from the network, for example with `buku --version` on the host where it is installed.\n- Confirm the installed version against the range stated in the sources: through `5.1.1`.","fix":"- Buku (bukuserver): a patch is linked in the sources, but no fixed version is stated; unknown.","status":"open","published_at":"2026-11-05T19:17:19+00:00","first_seen_at":"2026-11-05T19:40:36+00:00","triaged_at":"2026-11-05T19:43:31+00:00","updated_at":"2026-11-05T19:43:31+00:00","category":"package","confidence":0.6,"triage":{"at":"2026-11-05T19:43:31Z","model":"claude-haiku-5-5","output":{"fix":"- Buku (bukuserver): a patch is linked in the sources, but no fixed version is stated; unknown.","reach":"internet","title":"Buku bukuserver: unauthenticated request forgery lets remote users read internal services","impact":"medium","summary":"Buku's bukuserver web interface lets an unauthenticated remote attacker make the server request internal hosts through the url parameter of /api/fetch_data or /api/network_handle. The attacker can read the page titles, descriptions and keywords of loopback, private and cloud metadata addresses.","audience":"developers","category":"package","nicknames":[],"who_cares":["buku","bukuserver","python","self-hosted"],"confidence":0.6,"fix_status":"available","needs_auth":"no","worst_case":"Attacker reads internal service titles and metadata via server","analyst_note":"Confirm the fixed bukuserver version from the linked GitHub patch and check whether the setup is default-config or needs an option enabled.","how_to_check":"- Check whether bukuserver is running and reachable from the network, for example with `buku --version` on the host where it is installed.\n- Confirm the installed version against the range stated in the sources: through `5.1.1`.","plain_action":"","needs_analyst":true,"not_affected_if":["cli-only-use","bukuserver-not-running"],"who_is_affected":"Teams that run bukuserver, the web front end for the Buku bookmark manager, are exposed when it accepts requests from a network they do not control. The sources do not state a default configuration or whether authentication can be enabled. Installations that only run the buku command line tool on a single machine are not covered by this description.","user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"medium"},"cost_usd":0.001097,"input_tokens":4318,"output_tokens":1330,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-123201':14A,17A '-2026':13A,16A '/api/fetch_data':46B,96C '/api/network_handle':48B,98C '5.1.1':69C 'address':65B,108C 'allow':80C 'attack':34B,50B,82C,99C 'bad':114C 'buku':1A,18B,25B,66C 'bukuserv':2A,19B,27B,67C 'check':116C 'cloud':63B,105C 'contain':70C 'cve':12A,15A 'descript':56B,129C 'discov':121C 'follow':118C 'forgeri':5A,77C 'host':24B,40B,89C 'interfac':29B 'intern':10A,39B,88C,122C 'ip':107C 'keyword':58B,131C 'let':6A,30B 'loopback':60B,102C 'make':35B,84C 'metadata':64B,106C 'packag':20B 'page':54B,127C 'paramet':44B,94C 'pass':110C 'privat':61B,103C 'python':21B 'read':9A,52B,125C 'redirect':119C 'remot':7A,33B,81C 'request':4A,38B,76C,87C 'self':23B 'self-host':22B 'server':37B,74C,86C 'server-sid':73C 'servic':11A,123C 'side':75C 'suppli':91C 'target':101C 'titl':55B,128C 'unauthent':3A,32B,72C 'url':43B,93C,115C 'user':8A 'vulner':78C 'weak':112C 'web':28B","nicknames":[],"mitigations":[],"who_affected":"Teams that run bukuserver, the web front end for the Buku bookmark manager, are exposed when it accepts requests from a network they do not control. The sources do not state a default configuration or whether authentication can be enabled. Installations that only run the buku command line tool on a single machine are not covered by this description.","tier":"C","verified":{},"analyst_revisit_at":null,"fix_status":"available","audience":"developers","plain_action":null,"pkeys":[],"ptokens":[],"labels":["buku","bukuserver","medium","package","python","selfhosted"],"campaign_type":null,"first_public_at":"2026-11-05T19:17:19+00:00","kev":null,"cvss_vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","cvss_by":"disclosure@vulncheck.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-123201","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-123201","severity":null,"published_at":"2026-11-05T19:17:19+00:00","modified_at":"2026-11-05T19:17:19+00:00","first_seen_at":"2026-11-05T19:40:36+00:00","fetched_at":"2026-11-05T19:40:36+00:00","note":null}],"documents":[{"id":79195,"url":"https://github.com/jarun/buku/commit/13f6497afc974f02f1069b760772abe8815d1675","title":"Patch: github.com","kind":"other","source":"nvd","publisher":"vendor","text":null,"published_at":null,"relation":"fix","confidence":null,"note":"Patch: github.com"},{"id":79196,"url":"https://www.vulncheck.com/advisories/buku-through-5.1.1-ssrf-via-bukuserver-fetch-data-and-network-handle-api","title":"Third-party advisory: www.vulncheck.com","kind":"advisory","source":"nvd","publisher":"research","text":null,"published_at":null,"relation":"advisory","confidence":null,"note":"Third-party advisory: www.vulncheck.com"}],"exploit_sources":[],"notice":"Free to read, with fair use of about 60 pages a minute. For higher limits or API access: sales@infrastack.ai"}